Additive manufacturing build units with process gas inertization systems

ABSTRACT

A build unit for additively manufacturing three-dimensional objects may include an energy beam system having one or more irradiation devices respectively configured to direct one or more energy beams onto a region of a powder bed, and an inertization system including an irradiation chamber defining an irradiation plenum, one or more supply manifolds, and a return manifold. The one or more supply manifolds may include a downflow manifold configured to provide a downward flow of a process gas through at least a portion of the irradiation plenum defined by the irradiation chamber, and/or a crossflow manifold configured to provide a lateral flow of the process gas through at least a portion of the irradiation plenum defined by the irradiation chamber. The return manifold may evacuate or otherwise remove process gas from the irradiation plenum defined by the irradiation chamber. While irradiating the region of the powder bed, the process gas may flow through the one or more supply manifolds, into the irradiation plenum, and from the irradiation plenum into the return manifold.

FIELD

The present disclosure generally pertains to build units for additivemanufacturing systems, including build units for large format additivemanufacturing operations and/or build units with process gasinertization system.

BACKGROUND

Large format additive manufacturing systems or machines may include abuild unit and a build vessel, in which a cross-sectional surface areaof the build vessel significantly exceeds the cross-sectional surfacearea of the build unit. The build unit and/or the build vessel may bemovable relative to one another to additively manufacture relativelylarge objects and/or a relatively large quantity of objects within thebuild vessel.

Additive manufacturing operations that utilize a powder bed fusionprocess can be performed within an inertized processing environment,whereby inertized process gas may be supplied to a build chamber whilecontaminants such as soot, fumes, particulates, powder material, orother byproducts generated during the additive manufacturing operationmay be evacuated from the process chamber. However, additivemanufacturing systems or machines that include a build unit and a buildvessel that are movable relative to one another introduce uniquechallenges for providing an inertized processing environment.

Accordingly, improved additive manufacturing systems and machines,including improved build units that include process gas inertizationsystems, would be welcomed in the art.

BRIEF DESCRIPTION

Aspects and advantages will be set forth in part in the followingdescription, or may be apparent from the description, or may be learnedthrough practicing the presently disposed subject matter.

In one aspect, the present disclosure embraces additive manufacturingsystems and/or additive manufacturing machines. An exemplary additivemanufacturing system and/or additive manufacturing machine may include abuild unit, a build vessel, a build unit-positioning system, and/or abuild vessel-positioning system. The build unit, the build vessel, thebuild unit-positioning system, and the build vessel-positioning systemmay be configured according to the present disclosure.

In another aspect, the present disclosure embraces build units foradditively manufacturing three-dimensional objects. An exemplary buildunit may include an energy beam system, and an inertization system, oneor more supply manifolds, and a return manifold. The energy beam systemmay include one or more irradiation devices respectively configured todirect one or more energy beams onto a region of a powder bed. Theinertization system may include an irradiation chamber defining anirradiation plenum. The one or more supply manifolds may include adownflow manifold configured to provide a downward flow of a process gasthrough at least a portion of the irradiation plenum defined by theirradiation chamber. Additionally, or in the alternative, the one ormore supply manifolds may include a crossflow manifold configured toprovide a lateral flow of the process gas through at least a portion ofthe irradiation plenum defined by the irradiation chamber. In someembodiments, an exemplary build unit may include an inertization systemthat includes an irradiation chamber defining an irradiation plenum andone or more supply manifolds configured to supply a process gas to theirradiation plenum while irradiating the region of the powder bed withthe build unit situated above the region of the powder bed. The processgas may flow through the one or more supply manifolds and into theirradiation plenum while irradiating the region of the powder bed. Thereturn manifold may evacuate or otherwise remove process gas from theirradiation plenum defined by the irradiation chamber.

An exemplary downflow manifold may include a downflow manifold bodydefining one or more downflow manifold pathways within the downflowmanifold body. The downflow manifold body may include one or more inwarddownflow manifold walls defining an optics plenum coinciding with adistal portion of the irradiation plenum relative to the powder bed. Theone or more inward downflow manifold walls may diverge from alongitudinal axis of the downflow manifold body in a proximal directionrelative to the powder bed at a divergence angle allowing the one ormore energy beams of the energy beam system to access the portion of thepowder bed corresponding to a scan field of the one or more energybeams. The one or more inward downflow manifold walls may include aplurality of downflow manifold apertures fluidly communicating betweenthe optics plenum and one or more downflow manifold pathways defined bythe downflow manifold body. The plurality of downflow manifold aperturesmay be oriented parallel to a longitudinal axis of the downflow manifoldbody. In some embodiments, the plurality of downflow manifold aperturesmay be oriented within 10 degrees of parallel to the longitudinal axisof the downflow manifold body.

An exemplary crossflow manifold may include a plurality of crossflowmanifold bodies arranged along a width of the crossflow manifold. Theplurality of crossflow manifold bodies may be respectively coupled toone another or may define a respective integrally formed portion of thecrossflow manifold. Respective ones of the plurality of crossflowmanifold bodies may include a crossflow manifold inlet fluidlycommunicating with a process gas supply line and a plurality ofcrossflow manifold pathways defined by the respective crossflow manifoldbody. The crossflow manifold may include a crossflow manifold outletdefined at least in part by respective ones of the plurality ofcrossflow manifold bodies. The crossflow manifold outlet may fluidlycommunicate with the irradiation plenum defined by the irradiationchamber and the plurality of crossflow manifold pathways of therespective ones of the plurality of crossflow manifold bodies.

The crossflow manifold outlet may have an elongate cross-sectionalprofile. Respective ones of the plurality of crossflow manifold bodiesmay include a transverse expansion region and a lateral translationregion. The transverse expansion region may be located downstream fromthe respective crossflow manifold inlet. The lateral translation regionmay be located downstream from the transverse expansion region andupstream from the crossflow manifold outlet. The transverse expansionregion may exhibit a transverse expansion of the respective crossflowmanifold body relative to a longitudinal axis of the respectivecrossflow manifold inlet and/or relative to a lateral axis of thecrossflow manifold outlet. The lateral translation region may exhibit alateral translation in an axial orientation of the respective crossflowmanifold body relative to the longitudinal axis of the respectivecrossflow manifold inlet and/or relative to a lateral axis of thecrossflow manifold outlet.

An exemplary return manifold may include a plurality of return manifoldbodies arranged along a width of the return manifold. The plurality ofreturn manifold bodies may be respectively coupled to one another or maydefine a respective integrally formed portion of the return manifold.The return manifold may include a return manifold inlet defined at leastin part by respective ones of the plurality of return manifold bodies.Respective ones of the plurality of return manifold bodies may includeone or more return manifold pathways and a return manifold outletfluidly communicating with the one or more return manifold pathways ofthe return manifold body and a process gas evacuation line. The returnmanifold inlet may fluidly communicate with the irradiation plenumdefined by the irradiation chamber and the one or more return manifoldpathways defined by the respective ones of the plurality of returnmanifold bodies. The return manifold may be configured to receive alateral flow of the process gas from at least a portion of anirradiation plenum defined by the irradiation chamber. The returnmanifold inlet may have an elongate cross-sectional profile. The returnmanifold may include one or more narrowing regions and/or one or morerib elements disposed about the return manifold inlet and/or within theone or more return manifold pathways.

In yet another aspect, the present disclosure embraces methods ofadditively manufacturing a three-dimensional object. An exemplary methodmay include irradiating a powder bed with a build unit situated above apowder bed, flowing a process gas through the one or more supplymanifolds and into the irradiation plenum while irradiating the powderbed, and evacuating or otherwise removing the process gas from theirradiation plenum through the return manifold while irradiating thepowder bed. The build unit may include an energy beam system and aninertization system. The inertization system may include an irradiationchamber defining an irradiation plenum, one or more supply manifoldsconfigured to supply process gas to the irradiation plenum, and a returnmanifold configured to receive and/or evacuate process gas from theirradiation plenum. The one or more supply manifolds may include adownflow manifold configured to provide a downward flow of the processgas through at least a portion of the irradiation plenum defined by theirradiation chamber, and a crossflow manifold configured to provide alateral flow of the process gas through at least a portion of theirradiation plenum defined by the irradiation chamber.

In some embodiments, an exemplary method may include irradiating aregion of a powder bed with a build unit situated above the region ofthe powder bed and flowing a process gas through the one or more supplymanifolds and into the irradiation plenum while irradiating the powderbed. The build unit may include an energy beam system and aninertization system. The energy beam system may include one or moreirradiation devices respectively configured to direct one or more energybeams onto a region of a powder bed. The inertization system may includean irradiation chamber defining an irradiation plenum and one or moresupply manifolds configured to supply process gas to the irradiationplenum. The one or more supply manifolds may include a downflow manifoldconfigured to provide a downward flow of the process gas through atleast a portion of the irradiation plenum defined by the irradiationchamber. The downflow manifold may include a downflow manifold bodydefining one or more downflow manifold pathways within the downflowmanifold body, and one or more inward downflow manifold walls definingan optics plenum including a distal portion of the irradiation plenumrelative to the powder bed. The one or more inward downflow manifoldwalls may diverge from a longitudinal axis of the downflow manifold bodyin a proximal direction relative to the powder bed at a divergence angleallowing the one or more energy beams of the energy beam system toaccess the portion of the powder bed corresponding to a scan field ofthe one or more energy beams.

In some embodiments, flowing the process gas through the one or moresupply manifolds and into the irradiation plenum may include flowing theprocess gas through a plurality of downflow manifold apertures disposedwithin the one or more inward downflow manifold walls. The plurality ofdownflow manifold apertures may fluidly communicate between the opticsplenum and the one or more downflow manifold pathways defined by thedownflow manifold body. The plurality of downflow manifold apertures maybe oriented parallel to a longitudinal axis of the downflow manifoldbody or within 10 degrees of parallel to the longitudinal axis of thedownflow manifold body.

Additionally, or in the alternative, flowing the process gas through theone or more supply manifolds and into the irradiation plenum may includeflowing the process gas through a crossflow manifold configured toprovide a lateral flow of the process gas through at least a portion ofthe irradiation plenum defined by the irradiation chamber. The crossflowmanifold may include a plurality of crossflow manifold bodies arrangedalong a width of the crossflow manifold and respectively coupled to oneanother or defining a respective integrally formed portion of thecrossflow manifold. Respective ones of the plurality of crossflowmanifold bodies may include a crossflow manifold inlet fluidlycommunicating with a process gas supply line and a plurality ofcrossflow manifold pathways defined by the respective crossflow manifoldbody, and the crossflow manifold may include a crossflow manifold outletdefined at least in part by respective ones of the plurality ofcrossflow manifold bodies. The crossflow manifold outlet may have anelongate cross-sectional profile, and the crossflow manifold outlet mayfluidly communicate with the irradiation plenum defined by theirradiation chamber and the plurality of crossflow manifold pathways ofthe respective ones of the plurality of crossflow manifold bodies.

In some embodiments, flowing the process gas through the one or moresupply manifolds and into the irradiation plenum may includetransversely expanding the process gas at a transverse expansion regionof respective ones of the plurality of crossflow manifold bodies and/orby laterally translating the process gas at a lateral translation regionof respective ones of the plurality of crossflow manifold bodies. Thetransversely expanding the process gas may be followed by the laterallytranslating the process gas. The transverse expansion region may belocated downstream from the respective crossflow manifold inlet, and thelateral translation region may be located downstream from the transverseexpansion region and upstream from the crossflow manifold outlet. Thetransverse expansion region may exhibit a transverse expansion relativeto a longitudinal axis of the respective crossflow manifold inlet and/orrelative to a lateral axis of the crossflow manifold outlet. The lateraltranslation region may exhibit a lateral translation in an axialorientation of the respective crossflow manifold body relative to thelongitudinal axis of the respective crossflow manifold inlet and/orrelative to a lateral axis of the crossflow manifold outlet.

In some embodiments, the process gas may be evacuated or otherwiseremoved from the irradiation plenum through the return manifold whileirradiating the powder bed. Evacuating or otherwise removing the processgas from the irradiation plenum may include accelerating the process gasflowing into the return manifold inlet and/or through the one or morereturn manifold pathways by way of a pressure reduction within thereturn manifold inlet and/or within the one or more return manifoldpathways. The pressure reduction may be provided by one or morenarrowing regions and/or one or more rib elements disposed about thereturn manifold inlet and/or within the one or more return manifoldpathways. The return manifold may include a plurality of return manifoldbodies arranged along a width of the return manifold. The plurality ofreturn manifold bodies may be respectively coupled to one another or maydefine a respective integrally formed portion of the return manifold.The return manifold may include a return manifold inlet defined at leastin part by respective ones of the plurality of return manifold bodies,with respective ones of the plurality of return manifold bodiesincluding one or more return manifold pathways and a return manifoldoutlet fluidly communicating with the one or more return manifoldpathways of the respective return manifold body and a process gasevacuation line. The return manifold inlet may have an elongatecross-sectional profile, and the return manifold inlet may fluidlycommunicate with the irradiation plenum defined by the irradiationchamber and the one or more return manifold pathways defined by therespective ones of the plurality of return manifold bodies.

In yet another aspect, the present disclosure embraces computer-readablemedia. An exemplary computer-readable medium may include comprisingcomputer-executable instructions, which when executed by a processorassociated with an additive manufacturing machine, may cause theadditive manufacturing machine to perform a method of additivelymanufacturing a three-dimensional object. Exemplary methods that may beperformed by according to with the computer-executable instructions maybe configured as described in the present disclosure.

These and other features, aspects and advantages will become betterunderstood with reference to the following description and appendedclaims. The accompanying drawings, which are incorporated in andconstitute a part of this specification, illustrate exemplaryembodiments and, together with the description, serve to explain certainprinciples of the presently disposed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure, including the best mode thereof,directed to one of ordinary skill in the art, is set forth in thespecification, which makes reference to the appended Figures, in which:

FIGS. 1A and 1B schematically depict exemplary additive manufacturingsystems;

FIGS. 2A-2C schematically depict cross-sectional cutaway views of abuild unit and a build vessel of an additive manufacturing machine orsystem;

FIG. 2D schematically depicts a top view of a build unit and a buildvessel of an additive manufacturing machine or system;

FIGS. 3A-3D, respectively, schematically depict a perspective view of anexemplary irradiation chamber of a build unit;

FIG. 4A schematically depicts a top perspective view of an exemplarydownflow manifold for supplying downflow gas stream to a build unit;

FIG. 4B schematically depicts a cutaway top perspective view of anexemplary downflow manifold;

FIG. 4C schematically depicts a bottom perspective view of an exemplarydownflow manifold;

FIG. 4D schematically depicts a cutaway side view of an exemplarydownflow manifold;

FIG. 4E schematically depicts a cutaway perspective view of an exemplarydownflow manifold;

FIG. 5A schematically depicts a perspective view of an exemplarycrossflow manifold for supplying a crossflow gas stream to a build unit;

FIG. 5B schematically depicts a rear view of an exemplary crossflowmanifold;

FIG. 6A schematically depicts a top view of an exemplary flowconditioning vanes of a crossflow manifold;

FIG. 6B schematically depicts a perspective view of an exemplary inletflow conditioner for a crossflow manifold;

FIGS. 6C and 6D schematically depict a top view and a cross-sectionalview, respectively, of an exemplary inlet flow conditioner inserted in acrossflow manifold;

FIGS. 6E and 6F schematically depict a top view and a cross-sectionalview, respectively, of another exemplary inlet flow conditioner insertedin a crossflow manifold;

FIG. 7A schematically depicts a front view of an exemplary dischargeflow conditioner for a crossflow manifold;

FIGS. 7B and 7C schematically depicts a front view and a topcross-sectional view, respectively, of another exemplary discharge flowconditioner for a crossflow manifold;

FIGS. 8A and 8B schematically depicts a front view and a cutawayperspective view, respectively, of an exemplary return manifold;

FIGS. 9A-9C schematically depict a perspective view, a facing view, anda side view, respectively, of an exemplary crossflow wall for acrossflow chamber of a build unit;

FIGS. 9D and 9E schematically depict a facing view, and a side view,respectively, of another exemplary crossflow wall for a crossflowchamber of a build unit;

FIGS. 10A and 10B schematically depict exemplary flow vectorssuperimposed upon front and side cross-sectional views, respectively, ofan exemplary build unit;

FIG. 10C schematically depict exemplary flow vectors superimposed upon atop cross-sectional view taken at cross-section “A” shown in FIGS. 10Aand 10B;

FIGS. 10D-10F schematically depict additional exemplary flow vectorssuperimposed upon a top cross-sectional view taken at cross-section “A”shown in FIGS. 10A and 10B;

FIG. 11 schematically depicts an exemplary control system for anadditive manufacturing machine or system; and

FIG. 12 shows a flow chart depicting an exemplary method of additivelymanufacturing a three-dimensional object.

Repeat use of reference characters in the present specification anddrawings is intended to represent the same or analogous features orelements of the present disclosure.

DETAILED DESCRIPTION

The presently disclosed subject matter will now be described in furtherdetail, in some instances with reference to one or more of the drawings.Examples are provided by way of explanation and should not beinterpreted as limiting the present disclosure. In fact, it will beapparent to those skilled in the art that various modifications andvariations can be made in the present disclosure without departing fromthe scope of the present disclosure. For instance, features illustratedor described in one portion of the present disclosure can be used withfeatures illustrated or described in another portion of the presentdisclosure, including with modification and variations thereof. It isintended that the present disclosure covers such modifications andvariations as come within the scope of the appended claims and theirequivalents.

It is understood that terms “upstream” and “downstream” refer to therelative direction with respect to fluid flow in a fluid pathway. Forexample, “upstream” refers to the direction from which the fluid flows,and “downstream” refers to the direction to which the fluid flows. It isalso understood that terms such as “top”, “bottom”, “outward”, “inward”,and the like are words of convenience and are not to be construed aslimiting terms. As used herein, the terms “first”, “second”, and “third”may be used interchangeably to distinguish one component from anotherand are not intended to signify location or importance of the individualcomponents. The terms “a” and “an” do not denote a limitation ofquantity, but rather denote the presence of at least one of thereferenced item.

Approximating language, as used herein throughout the specification andclaims, may be applied to modify any quantitative representation thatcould permissibly vary without resulting in a change in the basicfunction to which it is related. Accordingly, a value modified by a termor terms, such as “about,” “substantially,” and “approximately,” are notto be limited to the precise value specified. In at least someinstances, the approximating language may correspond to the precision ofan instrument for measuring the value, or the precision of the methodsor machines for constructing or manufacturing the components and/orsystems. For example, the approximating language may refer to beingwithin a 10 percent margin.

Here and throughout the specification and claims, range limitations arecombined and interchanged, such ranges are identified and include allthe sub-ranges contained therein unless context or language indicatesotherwise. For example, all ranges disposed herein are inclusive of theendpoints, and the endpoints are independently combinable with eachother.

As described herein, the presently disclosed subject matter involves theuse of additive manufacturing machines or systems. As used herein, theterm “additive manufacturing” refers generally to manufacturingtechnology in which components are manufactured in a layer-by-layermanner. An exemplary additive manufacturing machine may be configured toutilize any desired additive manufacturing technology. The additivemanufacturing machine may utilize an additive manufacturing technologythat includes a powder bed fusion (PBF) technology, such as a directmetal laser melting (DMLM) technology, an electron beam melting (EBM)technology, an electron beam sintering (EBS) technology, a selectivelaser melting (SLM) technology, a directed metal laser sintering (DMLS)technology, or a selective laser sintering (SLS) technology. In anexemplary PBF technology, thin layers of powder material aresequentially applied to a build plane and then selectively melted orfused to one another in a layer-by-layer manner to form one or morethree-dimensional objects. Additively manufactured objects are generallymonolithic in nature and may have a variety of integral sub-components.

As used herein, the term “build plane” refers to a plane defined by asurface upon which an energy beam impinges during an additivemanufacturing process. Generally, the surface of a powder bed definesthe build plane; however, during irradiation of a respective layer ofthe powder bed, a previously irradiated portion of the respective layermay define a portion of the build plane, and/or prior to distributingpowder material across a build module, a build plate that supports thepowder bed generally defines the build plane.

Additionally or alternatively suitable additive manufacturingtechnologies include, for example, Binder Jet technology, FusedDeposition Modeling (FDM) technology, Direct Energy Deposition (DED)technology, Laser Engineered Net Shaping (LENS) technology, Laser NetShape Manufacturing (LNSM) technology, Direct Metal Deposition (DMD)technology, Digital Light Processing (DLP) technology, VatPolymerization (VP) technology, Stereolithography (SLA) technology, andother additive manufacturing technology that utilizes an energy beam.

Additive manufacturing technology may generally be described asfabrication of objects by building objects point-by-point,layer-by-layer, typically in a vertical direction; however, othermethods of fabrication are contemplated and within the scope of thepresent disclosure. For example, although the discussion herein refersto the addition of material to form successive layers, the presentlydisposed subject matter may be practiced with any additive manufacturingtechnology or other manufacturing technology, including layer-additiveprocesses, layer-subtractive processes, or hybrid processes.

The additive manufacturing processes described herein may be used forforming components using any suitable material. For example, thematerial may be metal, ceramic, polymer, epoxy, photopolymer resin,plastic, concrete, or any other suitable material that may be in solid,liquid, powder, sheet material, wire, or any other suitable form. Eachsuccessive layer may be, for example, between about 10 pm and 200 p.m,although the thickness may be selected based on any number of parametersand may be any suitable size.

The present disclosure generally pertains to build units for additivemanufacturing systems or machines that include a process gasinertization system. The presently disclosed build units may be utilizedwith large format additive manufacturing systems or machines thatinclude a build unit and a build vessel, for example, in which across-sectional surface area of the build vessel may significantlyexceed the cross-sectional surface area of the build unit. The buildunit and/or the build vessel may be movable relative to one another toadditively manufacture relatively large objects and/or a relativelylarge quantity of objects within the build vessel.

The build unit may include an inertization system that includes anirradiation chamber that defines an irradiation plenum, one or moresupply manifolds configured to supply process gas to one or more regionsof the irradiation chamber, and one or more return manifolds configuredto receive and/or evacuate process gas from one or more regions of theirradiation chamber. An energy beam system may be coupled to theirradiation chamber, and one or more optics windows may separate one ormore optical elements of the energy beam system from the irradiationplenum defined by the irradiation chamber. The one or more supplymanifolds may supply process gas, such as an inert gas, to theirradiation plenum, thereby providing an environment, such as an inertenvironment, suitable for irradiating powder material with one or moreenergy beams generated by the energy beam system. The one or more returnmanifolds may receive and/or evacuate process gas and contaminants fromthe irradiation plenum, such as soot, fumes, particulates, powdermaterial, or other byproducts generated during the additivemanufacturing operation.

The inertization system may be configured to provide one or more flowfields that improve the quality of the inertized environment within theirradiation chamber and/or that improve the efficiency with whichprocess gas is utilized and/or the effectiveness in which contaminantsare removed and/or evacuated from the process chamber. As used herein,the term “flow field” refers to a flow of process gas that has one ormore determinable bulk flow characteristics, such as a directionalvector, a velocity, a flow rate, a pressure, a boundary layer, and soforth.

An exemplary inertization system may include one or more downflowmanifolds that may provide a flow field of process gas, such as adownward flow field, that prevents contaminants within the irradiationchamber from contacting and/or depositing upon components of the energybeam system and/or that reduces the quantity of contaminants thatcontact and/or deposit upon components of the energy beam system overtime. Additionally, or in the alternative, an inertization system mayinclude one or more crossflow manifolds that provide a flow field ofprocess gas, such as a lateral flow field, that quickly removes orevacuates contaminants generated when an energy beam irradiates powdermaterial, for example, without the flow field disturbing the powder bed.Further, an inertization system may include one or more return manifoldsthat efficiently remove and/or evacuate process gas and/or contaminantsfrom the irradiation chamber, for example, without allowing much processgas to escape from the inertization system.

The presently disclosed subject matter will now be described in furtherdetail. FIGS. 1A and 1B schematically depict exemplary embodiments of anadditive manufacturing system 100. The additive manufacturing system 100may include one or more additive manufacturing machines 102. The one ormore additive manufacturing machines 102 may include a control system104. The control system 104 may include componentry integrated as partof the additive manufacturing machine 102 and/or componentry that isprovided separately from the additive manufacturing machine 102. Variouscomponentry of the control system 104 may be communicatively coupled tovarious componentry of the additive manufacturing machine 102.

The control system 104 may be communicatively coupled with a managementsystem 106 and/or a user interface 108. The management system 106 may beconfigured to interact with the control system 104 in connection withenterprise-level operations pertaining to the additive manufacturingsystem 100. Such enterprise level operations may include transmittingdata from the management system 106 to the control system 104 and/ortransmitting data from the control system 104 to the management system106. The user interface 108 may include one or more user input/outputdevices to allow a user to interact with the additive manufacturingsystem 100.

An additive manufacturing machine 102 may include one or more buildunits 110. Additionally, or in the alternative, an additivemanufacturing machine 102 may include a build vessel 112. The one ormore build units 110 may be configured to supply powder material 114 tothe build vessel 112. Additionally, or in the alternative, the one ormore build units 110 may be configured to selectively solidify thepowder material 114 to additively manufacture a three-dimensional object116. As shown in FIGS. 1A and 1B, an exemplary build unit 110 mayinclude an energy beam system 118, an irradiation chamber 120, and apowder module 122. The energy beam system 118 and the irradiationchamber 120 may be operably coupled to one another. An irradiationchamber 120 and a powder module 122 may be operably coupled to oneanother. Additionally, or in the alternative, an irradiation chamber 120and a powder module 122 may be provides as separate build units 110.

The additive manufacturing system 100 or additive manufacturing machine102 may be configured for large format additive manufacturing. Forexample, a build vessel 112 and/or one or more objects 116 additivelymanufactured therein may have a cross-sectional area that exceeds thecross-sectional area of the one or more build units 110 utilized toadditively manufacture the one or more objects 116. The one or morebuild units 110 and/or the build vessel 112 may be movable relative toperform large-format additive manufacturing operations.

As shown in FIG. 1A, the one or more build units 110 may be operablycoupled to a build unit-positioning system 124. The buildunit-positioning system 124 may be configured to move the one or morebuild units 110 to specified build coordinates and/or along specifiedbuild vectors corresponding to a three-dimensional cartesian coordinatesystem in accordance with control commands provided, for example, by thecontrol system 104. The control commands may be provided, for example,to carry out operations of the one or more build units 110 in accordancewith the present disclosure. The build unit-positioning system 124 mayinclude one or more build unit-gantry elements 126 configured to movablysupport the one or more build units 110. Respective build unit-gantryelements 126 may be configured to move the one or more build units 110in one or more directions, such as an X-direction, a Y-direction, and/ora Z-direction.

As shown in FIG. 1B, the one or more build vessels 112 may be operablycoupled to a build vessel-positioning system 128. The buildvessel-positioning system 128 may be configured to move the build vessel112 to specified build coordinates and/or along specified build vectorscorresponding to a three-dimensional cartesian coordinate system inaccordance with control commands provided, for example, by the controlsystem 104. The control commands may be provided, for example, to carryout operations of the one or more build units 110 in accordance with thepresent disclosure. The build vessel-positioning system 128 may includeone or more build vessel-gantry elements 130 configured to movablysupport the build vessel 112. Respective build vessel-gantry elements130 may be configured to move the build vessel 112 in one or moredirections, such as an X-direction, a Y-direction, and/or a Z-direction.

The one or more build vessels 112 may be operably coupled to a buildvessel-positioning system 128 in addition to, or in the alternative to,one or more build units 110 operably coupled to a build unit-positioningsystem 124. For example, an additive manufacturing machine 102 mayinclude a build vessel-positioning system 128 and one or more stationarybuild units 110. Additionally, or in the alternative, an additivemanufacturing machine 102 may include a build vessel-positioning system128 and a build unit-positioning system 124. The buildvessel-positioning system 128 may be configured to move a build vessel112 in one or more directions, and the build vessel-positioning system128 may be configured to move a build vessel 112 in one or moredirections. For example, the build vessel-positioning system 128 may beconfigured to move a build vessel 112 in an X-direction and/or aY-direction. Additionally, or in the alternative, the buildunit-positioning system 124 may be configured to move a build unit 110in a Z-direction.

A build vessel-positioning system 128 may be configured to move a buildvessel 112 horizontally while one or more build units 110 selectivelyirradiate portions of the powder material 114 in the build vessel 112.For example, the build vessel-positioning system 128 may be configuredto move a build vessel 112 in accordance with an X-Y coordinate system.Additionally, or in the alternative, a build unit-positioning system 124may be configured to move a build unit 110 horizontally while the buildunit 110 selectively irradiates portions of the powder material 114 inthe build vessel 112. For example, the build vessel-positioning system128 may be configured to move a build vessel 112 in accordance with anX-Y coordinate system. A vertical position of the one or more buildunits 110 and/or the build vessel 112 may be augmented in connectionwith the addition of sequential layers of powder material 114 to thebuild vessel 112 and selective irradiation of the respective layers ofpowder material 114 in the build vessel 112. The buildvessel-positioning system 128 may be configured to sequentially move thebuild vessel 112 vertically to provide room for the next sequentiallayer of powder material 114 to be added to the build vessel 112.Additionally, or in the alternative, the build unit-positioning system124 may be configured to sequentially move a build unit 110 verticallyto provide room for the next sequential layer of powder material 114 tobe added to the build vessel 112. Movements of the build unit 110 and/orthe build vessel 112 may be carried out before, during, or after,irradiating a sequential layer of powder material 114.

Referring now to FIGS. 2A-2D, aspects of an exemplary additivemanufacturing system 100 and/or additive manufacturing machine 102 willbe further described. As shown in FIGS. 2A-2D, an additive manufacturingsystem 100 and/or an additive manufacturing machine 102 may include oneor more build units 110 situated above a build vessel 112. An exemplarybuild unit 110 may include an energy beam system 118, an irradiationchamber 120, and an inertization system 200. As shown, for example, inFIGS. 2B an 2D, a build unit 110 may additionally or alternativelyinclude one or more powder modules 122.

As shown in FIGS. 2A-2D, the inertization system 200 may include one ormore supply manifolds 202 configured to supply process gas to one ormore regions of the irradiation chamber 120. Additionally, or in thealternative, the inertization system 200 may include one or more returnmanifolds 204 configured to receive and/or evacuate process gas from oneor more regions of the irradiation chamber 120. The irradiation chamber120 may define a plenum or space containing process gas, such as aninert gas, thereby providing an environment, such as an inertenvironment, suitable for irradiating powder material 114 with one ormore energy beams. The plenum or space within the irradiation chamber120 may sometimes be referred to as an irradiation plenum 121. Processgas may enter the irradiation plenum 121 defined by the irradiationchamber 120 through one or more supply manifolds 202. Process gas mayexit the irradiation chamber 120 through one or more return manifolds204. Process gas may flow through the irradiation chamber 120,traversing the irradiation plenum 121, along a flowpath from respectiveones of the one or more supply manifolds 202 to one or more of therespective ones of the one or more return manifolds 204. The one or moresupply manifolds 202 and/or the one or more return manifolds 204 may beoperably coupled to the irradiation chamber 120. Additionally, or in thealternative, the one or more supply manifolds 202 and/or the one or morereturn manifolds 204 may be integrally formed with at least a portion ofthe irradiation chamber 120 as a single component. Further additionally,or as another alternative, the one or more supply manifolds 202 and/orthe one or more return manifolds 204 may define at least a portion ofthe irradiation chamber 120.

Process gas may be supplied to one or more supply manifolds 202 by oneor more process gas supply lines 206. Process gas may be removed orevacuated from one or more return manifolds 204 by one or more processgas evacuation lines 208. The inertization system 200 may include one ormore fans, pumps, or the like (not shown) configured to supply a flow ofprocess gas to the process gas supply lines 206. The inertization system200 may include a process gas recirculation system (not shown)configured to recirculate process gas, such as from the one or moreprocess gas evacuation lines 208 and back to the one or more process gassupply lines 206. The recirculation system may include one or morescreens, filters, or the like not shown) configured to removecontaminants such as soot, fumes, particulates, powder material, orother byproducts from the powder material and/or the process gas thatmay be generated when irradiating powder material. The recirculatedprocess gas may be filtered, screened, or the like prior to beingsupplied to the one or more supply manifolds 202 and/or prior to beingsupplied to the one or more process gas supply lines 206.

An inertization system 200 may include one or more supply manifolds 202configured and arranged as a downflow manifold 210. One or more downflowmanifolds 210 may be configured to provide a downward flow of processgas through at least a portion of the irradiation chamber 120. Adownflow manifold 210 may fluidly communicate with one or more processgas supply lines 206. As shown, for example, in FIGS. 2A and 2C, adownflow manifold 210 may be disposed about an upward portion of theirradiation chamber 120, such as a distal portion of the irradiationchamber 120 relative to a build vessel 112. A downflow manifold 210 maybe coupled to the irradiation chamber 120. Additionally, or in thealternative, a downflow manifold 210 may be integrally formed with atleast a portion of the irradiation chamber 120 as a single component.Further additionally, or as another alternative, a downflow manifold 210may define at least a portion of an irradiation chamber 120.

As shown, for example, in FIGS. 2A and 2C, a supply manifold 202, suchas a downflow manifold 210, may surround at least a portion of a scanfield 212 of one or more energy beams 214 of an energy beam system 118.Additionally, or in the alternative, a supply manifold 202, such as adownflow manifold 210, may surround at least a portion of one or moreirradiation devices 216 of an energy beam system 118. Additionally, orin the alternative, a supply manifold 202, such as a downflow manifold210, may surround at least a portion of one or more monitoring devices218 of an energy beam system 118. The one or more monitoring devices 218may be integrated with an irradiation device 216 as part of a combineddevice (e.g., FIG. 2A) and/or the one or more monitoring devices 218 andthe one or more irradiation devices 216 may be provided as respectivelyseparate devices (e.g., FIG. 2D).

One or more components of an energy beam system 118 may be coupled to asupply manifold 202, such as a downflow manifold 210. For example, anenergy beam system housing 220 may be coupled to a supply manifold 202.The energy beam system housing 220 may include housing elementscorresponding to one or more irradiation devices 216 and/or housingelements corresponding to one or more monitoring devices 218.Additionally, or in the alternative, one or more components of an energybeam system 118, such as an energy beam system housing 220, may beintegrally formed with at least a portion of a supply manifold 202, suchas a downflow manifold 210, as a single component. Further additionally,or as another alternative, one or more components of an energy beamsystem 118, such as an energy beam system housing 220, may define atleast a portion of a supply manifold 202, such as a downflow manifold210.

A supply manifold 202, such as a downflow manifold 210, may provide aflow of process gas configured to protect components of the energy beamsystem 118 from contaminants within the irradiation chamber 120. Forexample, downward flow of process gas from a downflow manifold 210 mayprotect components of the energy beam system 118 from contaminantswithin the irradiation chamber 120. The downward flow of process gasfrom the downflow manifold 210 may provide a flow field that preventscontaminants within the irradiation chamber 120 from contacting and/ordepositing upon components of the energy beam system 118 and/or thatreduces the quantity of contaminants that contact and/or deposit uponcomponents of the energy beam system 118 over time. In addition, or asan alternative to a downward flow, a supply manifold 202 such as adownflow manifold 210 may provide a crossflow of process gas. Acrossflow of process gas may also protect components of the energy beamsystem 118 from contaminants within the irradiation chamber 120,including preventing contaminants from contacting and/or depositing uponcomponents of the energy beam system 118 and/or reducing the quantity ofcontaminants that contact and/or deposit upon components of the energybeam system 118 over time.

An inertization system 200 may include one or more supply manifolds 202configured and arranged as a crossflow manifold 222. One or morecrossflow manifolds 222 may be configured to provide a lateral flow ofprocess gas through at least a portion of the irradiation plenum 121defined by the irradiation chamber 120. One or more process gas supplylines 206 may fluidly communicate with a crossflow manifold 222. Aprocess gas supply line 206 may supply a first portion of a stream ofprocess gas to a downflow manifold 210 and a second portion of thestream of process gas to a crossflow manifold 222.

As shown, for example, in FIGS. 2B and 2C, a crossflow manifold 222 maybe disposed about a downward portion of the irradiation chamber 120,such as a proximal portion of the irradiation chamber 120 relative to abuild vessel 112. A crossflow manifold 222 may be disposed laterallyadjacent to a proximal portion of the irradiation chamber 120. Acrossflow manifold 222 may be coupled to the irradiation chamber 120.Additionally, or in the alternative, a crossflow manifold 222 may beintegrally formed with at least a portion of the irradiation chamber 120as a single component. Further additionally, or as another alternative,a crossflow manifold 222 may define at least a portion of an irradiationchamber 120.

In addition to one or more supply manifolds 202, an inertization system200 may include one or more return manifolds 204 configured to receiveand/or evacuate process gas from the irradiation plenum 121 defined bythe irradiation chamber 120.

As shown, for example, in FIG. 2C, a return manifold 204 may be disposedabout a downward portion of the irradiation chamber 120, such as aproximal portion of the irradiation chamber 120 relative to a buildvessel 112. A return manifold 204 may be disposed laterally adjacent toa proximal portion of the irradiation chamber 120. A return manifold 204may be coupled to the irradiation chamber 120. Additionally, or in thealternative, a return manifold 204 may be integrally formed with atleast a portion of the irradiation chamber 120 as a single component.Further additionally, or as another alternative, a return manifold 204may define at least a portion of an irradiation chamber 120. A returnmanifold 204 may be disposed opposite a crossflow manifold 222. Forexample, a crossflow manifold 222 and a return manifold 204 may bedisposed about respectively opposite sides of an irradiation chamber120. A lateral flow of process gas from a crossflow manifold 222 may bedirected at the return manifold 204. Additionally, or in thealternative, a downward flow from a downflow manifold 210 may bedirected at a return manifold 204.

The one or more return manifolds 204 may be configured to work incombination with one or more supply manifolds 202. For example, one ormore return manifolds 204 may be configured and arranged to receive aflow of process gas flowing through at least a portion of theirradiation plenum 121 defined by the irradiation chamber 120, such as aflow of process gas supplied from at least one of the one or more supplymanifolds 202. A return manifold 204 may be configured to receive a flowof process gas supplied by one or more crossflow manifolds 222, such asa lateral flow of process gas from the one or more crossflow manifolds222. Additionally, or in the alternative, a return manifold 204 may beconfigured to receive a flow of process gas supplied by one or moredownflow manifolds 210, such as a downward flow of process gas from theone or more downflow manifolds 210. A crossflow of process gas, such asfrom a crossflow manifold 222 to a return manifold 204, may beconfigured to provide a flow field that quickly remove and/or evacuatecontaminants generated by an energy beam irradiating powder material,for example, without disturbing the powder bed 227. The flow fieldprovided by a crossflow manifold 222 may remove and/or evacuatecontaminants from the irradiation plenum 121 defined by the irradiationchamber 120 before the contaminants have an opportunity to propagate toan upward region of the irradiation plenum 121 where components of theenergy beam system are located. Contaminants that are not entrained inthe lateral flow field may be redirected and/or accelerated into thelateral flow field by a downward flow field from a downflow manifold210.

An inertization system 200 may include one or more supply manifolds 202operably grouped with one or more return manifolds 204 with respect to acrossflow and/or a downflow. As shown in FIGS. 2A-2D, an inertizationsystem 200 may include one or more supply manifolds 202, such as one ormore downflow manifolds 210 and/or one or more crossflow manifolds 222,grouped with one or more corresponding return manifolds 204. As shown,for example, in FIG. 2C, a first crossflow manifold 222 may be pairedwith a first return manifold 204 with respect to a first crossflow, suchas a first lateral crossflow. Additionally, or in the alternative, asecond crossflow manifold 222 may be paired with a second returnmanifold 204 with respect to a second crossflow, such as a secondlateral crossflow. The first crossflow may have a flow field oriented ina first lateral direction and the second crossflow may have a secondflow field oriented in a second lateral direction that differs from thefirst lateral direction. For example, the first lateral direction maydiffer from the second lateral direction by about 90 degrees, such asfrom about 30 degrees to about 150 degrees.

As shown, for example, in FIG. 2B, a plurality of crossflow manifolds222 may be disposed adjacent to one another. Additionally, or in thealternative, a crossflow manifold 222 may be coupled to a plurality ofprocess gas supply lines 206. The plurality of process gas supply lines206 may fluidly communicate with the one or more crossflow manifolds 222at an interval along a width of the one or more process gas supply lines206. A supply manifold header 224 may distribute process gas between oneor more supply manifolds 202. For example, as shown, a supply manifoldheader 224 may distribute process gas between a downflow manifold 210and a crossflow manifold 222. A supply manifold header 224 may includeone or more supply header conjunction elements 226.

A supply manifold header 224 may include a plurality of process gassupply lines 206 configured as supply manifold distribution elements205, such as a plurality of crossflow manifold distribution elements 207and/or a plurality of downflow manifold distribution elements 209. Byway of example, as shown, a supply manifold header 224 may include afirst crossflow manifold distribution element 207 and a second crossflowmanifold distribution element 207. Additionally, or in the alternative,as shown, a supply manifold header 224 may include a first downflowmanifold distribution element 209 and a second downflow manifolddistribution element 209. One or more of the plurality of supplymanifold distribution elements 205 may fluidly communicate with oneanother, for example, by way of one or more supply header conjunctionelements 226. For example, a first end of a supply header conjunctionelement 226 may fluidly communicate with a first crossflow manifolddistribution element 207 and a second end of a supply header conjunctionelement 226 may fluidly communicate with a second crossflow manifolddistribution element 207. Additionally, or in the alternative, a firstend of a supply header conjunction element 226 may fluidly communicatewith a downflow manifold distribution element 209 and a second end of asupply header conjunction element 226 may fluidly communicate with asecond downflow manifold distribution element 209. One or more supplyheader conjunction elements 226 may allow a flow of process gas todistribute proportionally between respective crossflow manifolddistribution elements 207 and/or between respective pathways of acrossflow manifold 222.

A supply manifold header 224 may include one or more multiway fittings228. The one or more multiway fittings 228 may distribute process gas tothe plurality of supply manifold distribution elements 205, such as to aplurality of crossflow manifold distribution elements 207 and/or aplurality of downflow manifold distribution elements 209. A supplymanifold header 224 may be configured and arranged to provide a desiredflow rate flow rate of process gas, and/or to equalize a flow rate ofprocess gas, as between the plurality of supply manifold distributionelements 205, such as between a plurality of crossflow manifolddistribution elements 207 and/or a plurality of downflow manifolddistribution elements 209. For example, the respective supply manifolddistribution elements 205 may have respective internal diametersselected to provide a desired flow rate flow rate of process gas, and/orto equalize a flow rate of process gas as between respective supplymanifold distribution elements 205. Additionally, or in the alternative,a supply manifold header 224 may include one or more supply headervalves 230. The one or more supply header valves 230 may be configuredto regulate a flow of process gas between one or more supply manifolds202, such as between a downflow manifold 210 and one or more crossflowmanifolds 222. One or more supply header valves 230 may be integratedinto a respective one of one or more multiway fittings 228.Additionally, or in the alternative, one or more one or more supplyheader valves 230 may be provided separately from one or more multiwayfittings 228. A supply header valve 230 may be actuated manually orautomatically. For example, one or more supply header valves may becontrolled by a control system 104, such as to provide a desire flowrate of process gas, and/or to equalize a flow rate of process gas, asbetween the plurality of supply manifold distribution elements 205, suchas between a plurality of crossflow manifold distribution elements 207and/or a plurality of downflow manifold distribution elements 209.

As shown in FIG. 2C, a flow of process gas from the one or more processgas supply line 206 to the crossflow manifold 222 may have a downwarddirectional vector 260. Additionally, or in the alternative, process gasflowing from one or more downflow manifolds 210 into the irradiationplenum 121 defined by the irradiation chamber 120 may have a downwarddirectional vector 260. A flow of process gas flowing across theirradiation plenum 121 defined by the irradiation chamber 120, such asfrom a crossflow manifold 222 to a return manifold 204, may have alateral directional vector 262. A crossflow manifold 222 may beconfigured to conform a flow of process gas from one or more process gassupply lines 206 having a downward directional vector 260 into a flow ofprocess gas having a lateral directional vector 262, for example, tosupply a crossflow of process gas to the irradiation chamber 120.Process gas flowing through the crossflow manifold 222 may have alaterally accelerating directional vector 264, for example, as thedirectional flow of the process gas changes from a downward direction toa lateral direction. The process gas flowing laterally across theirradiation plenum 121 defined by the irradiation chamber 120 may flowinto one or more return manifolds 204. Process gas with a lateraldirectional vector 262, such as from one or more crossflow manifolds222, may flow laterally into one or more return manifolds 204. Processgas flowing through the irradiation plenum 121 with a downwarddirectional vector 260, such as from one or more downflow manifolds 210,may also flow into one or more return manifolds 204. The downwarddirectional vector 260 of such process gas may be at least partiallyconformed to a lateral directional vector 262, for example, by way ofentrainment by a crossflow of process gas from the one or more crossflowmanifolds 222 and/or by way of suction from the one or more returnmanifolds 204. Process gas flowing from the irradiation plenum 121 intoa return manifold 204 may have a laterally accelerating directionalvector 264, for example, as the directional flow of the process gaschanges from a downward direction to a lateral direction. A returnmanifold 204 may be configured to conform a flow of process gas having alateral directional vector 262 entering the return manifold 204 to aflow of process gas having an upward directional vector 266 flowing fromthe return manifold into one or more process gas evacuation lines 208,for example, to remove and/or evacuate process gas from the irradiationplenum 121 defined by the irradiation chamber 120. Process gas flowingthrough the return manifold 204 may have an upward acceleratingdirectional vector 268, for example, as the directional flow of theprocess gas changes from a lateral direction to an upward direction.

An inertization system 200 may include a plurality of supply manifolds202 and corresponding return manifolds 204 oriented at a series oflongitudinal positions of the irradiation chamber 120. For example, afirst supply manifold 202, such as a crossflow manifold 222, and a firstreturn manifold 204, may be respectively oriented about a firstlongitudinal region of the irradiation chamber 120. A second supplymanifold 202, such as a crossflow manifold 222, and a second returnmanifold 204, may be respectively oriented at a second longitudinalregion of the irradiation chamber 120. The first longitudinal region mayinclude a relatively proximal portion of the irradiation chamber 120relative to the build vessel 112, and the second longitudinal region mayinclude a relatively midward portion of the irradiation chamber 120and/or a relatively distal portion of the irradiation chamber 120relative to the first longitudinal region and/or relative to the buildvessel 112. The first supply manifold 202 may provide a first crossflowthat has a flow field oriented in a first lateral direction, and thesecond supply manifold 202 may provide a second crossflow that has asecond flow field oriented in a second lateral direction that differsfrom the first lateral direction, for example, by about 90 degrees, suchas from about 30 degrees to about 150 degrees.

Referring again to FIGS. 2A and 2C, an energy beam system 118 mayinclude one or more irradiation devices 216. The one or more irradiationdevices 216 respectively configured to generate a one or more energybeams 214 and to direct the energy beams 214 upon a powder bed 227defining a build plane 225. The build plane 225 defined by the powderbed 227 may include, for example, by a next sequential layer of powdermaterial 114 distributed across the object 116 being additivelymanufactured and/or across unsolidified powder material 114 within thepowder bed 227. A build unit 110, including the energy beam system 118and the inertization system 200, may be situated above a region of thepowder bed 227 to be irradiated by the one or more irradiation devices216. The one or more energy beams 214 may be utilized to selectivelyirradiate a portion of the powder bed 227 above which the build unit 110is situated. The irradiation chamber 120 may provide an irradiationplenum 121 that includes a process gas, such as an inert process gas,above the region of the powder bed 227 situated below the build unit 110and/or the irradiation chamber 120.

An irradiation device 216 may be configured to generate a laser beam, anelectron beam, or any other energy beam suitable for additivemanufacturing. The irradiation device may be configured to cause theenergy beam 214 to selectively solidify respective portions of thepowder bed 227 defining the build plane 225. As the respective energybeams 214 selectively melt or fuse the sequential layers of powdermaterial 114 that define the powder bed 227, the object 116 begins totake shape. Typically, with a DMLM, EBM, or SLM system, the powdermaterial 114 is fully melted, with respective layers being melted orre-melted with respective passes of the energy beams. Conversely, withDMLS or SLS systems, typically the layers of powder material 114 aresintered, fusing particles of powder material 114 to one anothergenerally without reaching the melting point of the powder material 114.The energy beam system 118 may include componentry integrated as part ofthe additive manufacturing machine 102, such as componentry integratedas part of a build unit 110. Additionally, or in the alternative, theenergy beam system 118 may include componentry provided separately fromthe additive manufacturing machine 102 and/or separately from the buildunit 110.

As shown, for example, in FIG. 2A, the energy beam system 118 mayinclude one or more irradiation devices 216, and respective ones of theone or more irradiation devices 216 may respectively include an energybeam source 231, a scanner 232, and one or more optical elements 233configured to condition and/or focus an energy beam 214 onto the buildplane 225. Respective ones of the one or more irradiation devices 216may be separated from the irradiation chamber 120 by one or more opticswindows 234. The one or more optics windows 234 may separate one or moreoptical elements 233 of the energy beam system 118 from the irradiationplenum 121 defined by the irradiation chamber 120. For example, the oneor more optics windows 234 may separate one or more optical elements 233of an irradiation device 216 from the irradiation plenum 121.Additionally, or in the alternative, the one or more optics windows 234may separate one or more optical elements 233 of a monitoring device 218from the irradiation plenum 121. The one or more optics windows 234 mayseparate the one or more optical elements 233 from an optics plenum 235defining a portion of the irradiation plenum 121 adjacent to the supplymanifold 202, such as a downflow manifold 210. The one or more opticswindows 234 may be supported by at least a portion of the energy beamsystem housing 220. The one or more optics windows 234 may define a topportion of the optics plenum 235.

The one or more optics windows 234 and/or at least a portion of theenergy beam system housing 220 supporting the one or more optics windows234 may be configured to fit at least partially within an optics plenum235 defined by a supply manifold 202, such as a downflow manifold 210.Additionally, or in the alternative, the one or more optics windows 234and/or at least a portion of the energy beam system housing 220supporting the one or more optics windows 234 may be supported above theoptics plenum 235 by the supply manifold 202, such as the downflowmanifold 210. The supply manifold, such as the downflow manifold 210,may circumferentially surround the optics plenum 235. The optics plenum235 may be adjacent to the optics window 234. The supply manifold 202,such as the downflow manifold 210, may surround at least a portion ofthe one or more optics windows 234. The one or more optics windows 234and/or the at least a portion of the energy beam system housing 220supporting the one or more optics windows 234 may define a portion ofthe supply manifold 202, such as the downflow manifold 210. Theinertization system 200 may be configured to provide one or more flowfields that prevent contaminants in the irradiation plenum 121 fromcontacting and/or depositing upon the one or more optics windows 234and/or other components of the energy beam system 118, and/or thatreduces the quantity of contaminants that contact and/or deposit uponthe one or more optics windows 234 and/or other components of the energybeam system 118 over time.

A supply manifold 202, such as a downflow manifold 210 may define anoptics plenum 235 configured and arranged to interchangeably accommodatea selected one of a plurality of different energy beam systems 118, suchas a selected one of a plurality of different irradiation devices 216and/or a selected one of a plurality of different monitoring devices218, and/or a selected one of a plurality of different optical elements233 thereof. As shown, the optics plenum 235 may have an elongatecross-sectional surface area, such as an elongate rectangularcross-sectional surface area, configured to accommodate a plurality ofadjacently disposed optical elements 233. By way of example, as shown inFIG. 2D, a downflow manifold 210 may be configured and arranged toaccommodate two irradiation devices 216 and two monitoring devices 218.However, it will be appreciated that the embodiment shown in FIG. 2D isnot to be limiting, and in various embodiments a supply manifold 202,such as a downflow manifold 210, may accommodate any number ofirradiation devices 216 and/or any number of monitoring devices 218.

As shown in FIG. 2A, the energy beam system 118 includes a firstirradiation device 216 a and a second irradiation device 216 b. In otherembodiments, an energy beam system 118 may include three, four, six,eight, ten, or more irradiation devices 216. The plurality ofirradiation devices 216 may be configured to respectively generate oneor more energy beams 214 that are respectively scannable within a scanfield 212 incident upon at least a portion of the build plane 225. Forexample, the first irradiation device 216 a may generate a first energybeam 214 a that is scannable within a first scan field 212 a incidentupon at least a first build plane region 236 a. The second irradiationdevice 216 b may generate a second energy beam 214 b that is scannablewithin a second scan field 212 b incident upon at least a second buildplane region 236 b. The first scan field 212 a and the second scan field212 b may overlap such that the first build plane region 236 a scannableby the first energy beam 214 a overlaps with the second build planeregion 236 b scannable by the second energy beam 214 b. The overlappingportion of the first build plane region 236 a and the second build planeregion 236 b may sometimes be referred to as an interlace region 238.Portions of the powder bed 227 to be irradiated within the interlaceregion 238 may be irradiated by the first energy beam 214 a and/or thesecond energy beam 214 b in accordance with the present disclosure.

As shown, for example, in FIGS. 2B and 2D, a build unit 110 may includeone or more powder modules 122. The one or more powder modules 122 maybe coupled to an irradiation chamber 120 and/or to one or more supplymanifolds 202. Additionally, or in the alternative, one or more powdermodules 122 may be provided as separate build units 110. The one or morepowder modules 122 may be configured to move in coordination with theirradiation chamber 120, for example, as respective parts of a combinedbuild unit 110 and/or as separate cooperatively operated build units110.

The powder module 122 may contain a supply of powder material 114 housedwithin a supply chamber 240. The powder module 122 may be coupled to anirradiation chamber 120 by one or more powder module-supports 242. Thepowder module 122 includes a dosing mechanism 244 configured to dispensepowder material 114 from the supply chamber 240. The dosing mechanism244 may include a piston 246 configured to open and/or close a powderdoor 248. As the dosing mechanism 244 actuates, a portion of the powdermaterial 114 may be discharged out of the powder module 122. A recoater250 such as a blade or roller may sequentially distribute thin layers ofpowder material 114 across the build plane 225.

To irradiate a layer of the powder bed 227, the one or more irradiationdevices 216 may respectively direct the one or more energy beams 214across the respective portions of the build plane 225 to melt or fusethe portions of the powder material 114 that are to become part of theobject 116 being additively manufactured. The build unit-positioningsystem 124 may move the build unit 110 laterally to position therespective scan fields 212 above specified portions of the build plane225. Additionally, or in the alternative, the build vessel-positioningsystem 128 may move the build vessel 112 laterally to position therespective scan fields 212 above specified portions of the build plane225. As sequential layers of the powder material 114 are melted or fusedto one another, the build vessel-positioning system 128 may sequentiallygradually lower the build vessel 112 to make room for the recoater 250to distribute sequential layers of powder material 114. The recoater 250may include one or more recoater blades 252 or the like configured toprovide a smooth layer of powder material 114. Additionally, or in thealternative, the build unit-positioning system 124 may sequentiallygradually elevate the build unit 110 to make room for the recoater 250to distribute sequential layers of powder material 114. As sequentiallayers of powder material 114 are applied across the build plane 225,the next sequential layer of powder material 114 defines the surface ofthe powder bed 227 coinciding with the build plane 225. Sequentiallayers of the powder bed 227 may be selectively melted or fused until acompleted object 116 has been additively manufactured.

Still referring to FIGS. 2A-2D, an additive manufacturing machine 102may include a monitoring system 254. The monitoring system 254 mayinclude one or more monitoring devices 218 configured to detect amonitoring beam (not shown) such as an infrared beam from a laser diodeand/or a reflected portion of an energy beam 214, and to determine oneor more parameters associated with irradiating the sequential layers ofthe powder bed 227 based at least in part on the detected monitoringbeam. The build unit-positioning system 124 may move the build unit 110laterally to position the respective monitoring devices 218 abovespecified portions of the build plane 225. Additionally, or in thealternative, the build vessel-positioning system 128 may move the buildvessel 112 laterally to position the respective monitoring devices 218above specified portions of the build plane 225.

The one or more parameters determined by the monitoring system 254 maybe utilized, for example, by the control system 104, to control one ormore operations of the additive manufacturing machine 102 and/or of theadditive manufacturing system 100. The monitoring system 254 may beconfigured to project a monitoring beam (not shown) and to detect aportion of the monitoring beam reflected from the build plane 225.Additionally, and/or in the alternative, the monitoring system 254 maybe configured to detect a monitoring beam that includes radiationemitted from the build plane 225, such as radiation from an energy beamreflected from the powder bed 227 and/or radiation emitted from a meltpool in the powder bed 227 generated by an energy beam and/or radiationemitted from a portion of the powder bed 227 adjacent to the melt pool.

The monitoring system 254 may include componentry integrated as part ofthe additive manufacturing machine 102 and/or componentry that isprovided separately from the additive manufacturing machine 102. Forexample, the monitoring system 254 may include componentry integrated aspart of the energy beam system 118 and/or componentry integrated as partof a build unit 110. Additionally, or in the alternative, the monitoringsystem 254 may include separate componentry, such as in the form of anassembly, that can be installed as part of the energy beam system 118and/or as part of the additive manufacturing machine 102, and/or as partof a separate build unit 110.

Now turning to FIGS. 3A-3D, exemplary irradiation chambers 120 will befurther described. An irradiation chamber 120 may define an irradiationplenum 121, which may contain process gas, such as inert gas, suitablefor irradiating at least a portion of a build plane 225. The irradiationplenum 121 may be defined by one or more irradiation chamber walls 300.The one or more irradiation chamber walls 300 may define portions of anintegrally formed component. Additionally, or in the alternative, theone or more irradiation chamber walls 300 may include separate wallelements 302 coupled to one another. One or more supply manifolds 202and/or one or more return manifolds 204 may define at least a portion ofan irradiation chamber 120 and/or at least a portion of the irradiationplenum 121 defined by the one or more irradiation chamber walls 300. Abottom portion 304 of the irradiation plenum 121 defined by theirradiation chamber 120, and/or the irradiation chamber walls 300thereof, may be at least partially open to the build plane 225. A topportion 306 of the irradiation plenum 121 defined by the irradiationchamber 120, and/or the irradiation chamber walls 300 thereof, may bedefined at least in part by an energy beam system 118 and/or one or moreoptics windows 234. Additionally, or in the alternative, the top portion306 of the irradiation plenum 121 defined by the irradiation chamber120, and/or the irradiation chamber walls 300 thereof, may be at leastpartially open for receiving an energy beam system 118 and/or one ormore optics windows 234.

An irradiation chamber 120 may include a downflow chamber 308 and/or acrossflow chamber 310. For example, an irradiation chamber 120 mayinclude a downflow chamber 308 coupled to a crossflow chamber 310. Thedownflow chamber 308 may be disposed about a distal portion of theirradiation chamber 120 relative to the build plane 225. The downflowchamber 308 may define a downflow plenum 309. The downflow plenum 309may include or refer to at least a portion of the irradiation plenum 121in which the process gas exhibits a downflow. A downflow chamber 308 maybe defined at least in part by a downflow manifold 210. Additionally, orin the alternative, a downflow chamber 308 may be defined at least inpart by one or more irradiation chamber walls 300 and/or wall elements302. Such one or more irradiation chamber walls 300 and/or wall elements302 may be coupled to a downflow manifold 210 and/or integrally formedwith the downflow manifold 210 as a single component. The crossflowchamber 310 may be disposed about a proximal portion of the irradiationchamber 120 relative to the build plane 225. The crossflow chamber 310may define a crossflow plenum 311. The crossflow plenum 311 may includeor refer to at least a portion of the irradiation plenum 121 in whichprocess gas exhibits a crossflow. A downflow chamber 308 may include oneor more downflow walls 312 coupled to a downflow manifold 210 and/orintegrally formed with the downflow manifold 210 as a single component.A crossflow chamber 310 may be defined at least in part by a crossflowmanifold 222 and/or at least in part by a return manifold 204.Additionally, or in the alternative, a crossflow chamber 310 may bedefined at least in part by one or more irradiation chamber walls 300and/or wall elements 302. Such one or more irradiation chamber walls 300and/or wall elements 302 may be coupled to a crossflow manifold 222and/or a return manifold 204, and/or integrally formed with thecrossflow manifold 222 and/or the return manifold 204 as a singlecomponent. A crossflow chamber 310 may include one or more crossflowwalls 314 coupled to a crossflow manifold 222 and/or a return manifold204, and/or integrally formed with the crossflow manifold 222 and/or thereturn manifold 204 as a single component.

The irradiation chamber 120, and/or the irradiation plenum 121 definedby an irradiation chamber 120 and/or by one or more irradiation chamberwalls 300 thereof, may exhibit any desired three-dimensional shape,including a prism, a cylinder, a frustum, or the like, as well ascombinations of these. By way of example, FIGS. 3A and 3B show exemplaryan irradiation chambers 120 that exhibit a prism shape. As shown inFIGS. 3A and 3B, an irradiation chamber 120 may have a rectangular prismshape. By way of further examples, FIGS. 3C and 3D show exemplaryirradiation chambers 120 and/or exemplary irradiation plenums 121 thatexhibit a cylinder shape. As shown in FIG. 3C, an irradiation chamber120 and/or an irradiation plenum 121 may exhibit a frustum shape. Theexamples shown in FIGS. 3A-3D are provided by way of example only andare not intended to be limiting. Numerous other configurations andarrangements are contemplated, including combinations of the examplesprovided, all of which are within the scope of the present disclosure.

As used herein, the term “prism” refers to a polyhedron with an n-sidedpolygonal base and an n-sided polygonal top. A prism may include ann-sided polygonal base and a top that represents a translation of then-sided polygonal base. The polygonal base and the polygonal top mayhave a different number of sized. As used herein, the term “cylinder”refers to a three-dimensional shape bounded by an elliptical bottom andan elliptical top. The elliptical top and/or the elliptical bottom of acylinder may include any elliptical shape, including a circle, an oval,or the like. As used herein, the term “frustum” refers to a prism or acylinder with a base and a top that have respectively different sizes.For example, a frustum may include an n-sided polygonal base and ann-sided polygonal top that have respectively different sizes. As anotherexample, a frustum may include an elliptical base and an elliptical topthat have respectively different sizes.

The one or more downflow walls 312 and/or the one or more crossflowwalls 314 may be oriented parallel and/or oblique to a longitudinal axis316 of the irradiation chamber 120 and/or crossflow chamber 310. The oneor more downflow walls 312 and/or the one or more crossflow walls 314may be oriented parallel and/or oblique to a lateral axis 318 of theirradiation chamber 120 and/or crossflow chamber 310. Additionally, orin the alternative, one or more downflow walls 312 and/or the one ormore crossflow walls 314 may have a curvilinear orientation with one ormore tangents that are parallel and/or oblique relative to thelongitudinal axis 316 of the irradiation chamber 120 and/or crossflowchamber 310. The one or more downflow walls 312 and/or the one or morecrossflow walls 314 may have a curvilinear orientation with one or moretangents that are parallel and/or oblique relative to the lateral axis318 of the irradiation chamber 120 and/or crossflow chamber 310.

FIGS. 3A-3C show exemplary irradiation chambers 120 with downflow walls312 oriented parallel to the longitudinal axis 316 of the irradiationchamber 120. FIGS. 3A-3C also show exemplary crossflow chambers 310 withcrossflow walls 314 oriented parallel to the longitudinal axis 316 ofthe irradiation chamber 120. FIG. 3D shows an exemplary irradiationchamber 120 with one or more downflow walls oriented oblique to thelongitudinal axis 316 of the crossflow chambers 310. FIG. 3D also showsan exemplary crossflow chamber 310 with one or more downflow wallsoriented oblique to the longitudinal axis 316 of the crossflow chambers310.

The one or more downflow walls 312 and/or the one or more crossflowwalls 314 may be oriented parallel and/or oblique to a lateral axis 318of the irradiation chamber and/or crossflow chamber 310. The lateralaxis 318 may be aligned with a lateral flow field discharged from acrossflow chamber 310. Additionally, or in the alternative, one or moredownflow walls 312 and/or one or more crossflow walls 314 may have acurvilinear orientation with one or more tangents that are paralleland/or oblique relative to the lateral axis 318 of the irradiationchamber 120 and/or crossflow chamber 310.

FIGS. 3A and 3C show exemplary irradiation chambers 120 with downflowwalls 312 oriented parallel to the lateral axis 318 of the irradiationchamber 120. FIGS. 3A and 3C also show exemplary crossflow chambers 310with crossflow walls 314 oriented parallel to the lateral axis 318 ofthe irradiation chamber 120. FIG. 3B shows an exemplary irradiationchamber 120 with one or more downflow walls 312 oriented oblique to thelateral axis 318 of the irradiation chamber 120. FIG. 3B also shows anexemplary crossflow chamber 310 with one or more crossflow walls 314oriented oblique to the lateral axis 318 of the crossflow chamber 310.An exemplary irradiation chamber 120 may include one or more downflowwalls 312 oriented laterally and oblique to the lateral axis 318 of theirradiation chamber 120 and one or more downflow walls 312 orientedtransversely and perpendicular to the lateral axis of the irradiationchamber 120. An exemplary crossflow chamber 310 may include one or morecrossflow walls 314 oriented laterally and oblique to the lateral axis318 of the crossflow chamber 310 and one or more crossflow walls 314oriented transversely and perpendicular to the lateral axis of thecrossflow chamber 310. FIG. 3D shows an exemplary irradiation chamber120 with one or more curvilinear downflow walls 312 with one or moretangents oriented parallel and/or oblique to the lateral axis 318 of theirradiation chamber 120. FIG. 3D also shows an exemplary crossflowchamber 310 with one or more curvilinear crossflow walls 314 with one ormore tangents oriented parallel and/or oblique to the lateral axis 318of the crossflow chamber 310.

An irradiation chamber 120 and/or an irradiation plenum 121 may exhibita change in one or more dimensions corresponding at least in part to adirectional vector of a flow field. One or more dimensions of theirradiation chamber 120 and/or an irradiation plenum 121 may increase ordecrease corresponding at least in part with a directional vector of aflow field. As shown, for example, in FIG. 3D, a downflow manifold 210may provide a downward flow field with a downward directional vector260. The cross-sectional width and/or cross-sectional area of theirradiation chamber 120 and/or an irradiation plenum 121 may increaseand/or decrease along the direction of the downward directional vector260. As shown, for example, in FIG. 3B, a crossflow manifold 222 mayprovide a lateral flow field with a lateral directional vector 262. Thecross-sectional width and/or cross-sectional area of the irradiationchamber 120 and/or an irradiation plenum 121 may increase and/ordecrease along the direction of the lateral directional vector 262.

As shown, for example, in FIG. 3B, a cross-sectional width and/orcross-sectional area of the irradiation chamber 120 and/or anirradiation plenum 121 may decrease along the direction of a lateraldirectional vector 262, such as from a crossflow manifold 222 to areturn manifold 204, and/or across at least a portion of a crossflowchamber 310. Such a decreasing cross-sectional width and/or area mayimprove the fluid properties of the lateral flow field. For example, adecreasing cross-sectional width and/or area may provide for an improvedvelocity profile, such as an improved uniformity across the width of thelateral flow field. Additionally, or in the alternative, a tendency forbackflow and/or eddies along the edges of the lateral flow field may bereduced by providing a decreasing cross-sectional width and/or areaacross at least a portion of a crossflow chamber 310, such as across atleast a portion of the lateral flowpath from a crossflow manifold 222 toa return manifold 204.

An irradiation chamber 120 and/or an irradiation plenum 121, and/or acrossflow chamber 310, with a decreasing cross-sectional width and/orarea may increase the velocity of the lateral flow field as the lateralflow of process gas approaches the return manifold 204. A velocitygradient may exist in the lateral flow field of process gas, forexample, increasing from the crossflow manifold 222 to the returnmanifold 204, and/or across at least a portion of the crossflow chamber310. Such an increasing velocity gradient may provide for sufficientlyhigh velocity in the flow field to move contaminants in the process gasout of the process chamber and into the one or more return manifolds204, for example, rather than such contaminants redepositing upon thepowder bed 227. Additionally, or in the alternative, a lateral flowfield with a sufficiently large lateral directional vector may providefor at least partial stratification in the lateral flow field, such asin the crossflow chamber 310. For example, a lateral flow field mayexhibit stratification as between at least a portion of the lateral flowfield corresponding to process gas from the crossflow manifold 222 andat least a portion of the lateral flow field corresponding to processgas from the downflow manifold 210.

As shown, for example, in FIG. 3D, a cross-sectional width and/orcross-sectional area of the irradiation chamber 120 and/or anirradiation plenum 121 may increase in the direction of a downwarddirectional vector 260, such as from a downflow manifold 210 and/ordownflow chamber 308 to the crossflow chamber 310. Such an increasingcross-sectional width and/or area may reduce the velocity of thedownward flow field as the downward flow of process gas approaches thebuild plane 225. A velocity gradient may exist in the downward flowfield of process gas, for example, decreasing from the downflow manifold210 and/or downflow chamber 308 to the crossflow chamber 310. Such adecreasing velocity gradient may provide for sufficiently high velocityin the flow field near the one or more optics windows 234 and/or othercomponents of the energy beam system 118 for protecting the one or moreoptics windows 234 and/or other components of the energy beam system 118while also providing sufficiently low velocity in the flow field nearthe crossflow chamber 310 and/or the powder bed 227 to avoid thedownward flow of process gas from disrupting the powder bed 227.Additionally, or in the alternative, the decreasing velocity gradientmay enhance entrainment of process gas in the downward flow field byprocess gas in the lateral flow field. Such entrainment of downwardflowing process gas by the lateral flow field may help draw the downwardflowing process gas into one or more return manifolds 204, such as bytransitioning the downward flow field to a lateral flow field.

Now turning to FIGS. 4A-4E, exemplary downflow manifolds 210 will befurther described. As shown, a downflow manifold 210 may include adownflow manifold body 400. The downflow manifold body 400 maycircumferentially surround the optics plenum 235. The downflow manifoldbody 400 may be in fluid communication with one or more process gassupply lines 206. The one or more process gas supply lines 206 mayfluidly communicate directly with the downflow manifold body 400.Additionally, or in the alternative, a downflow manifold 210 may includea supply manifold header 224 configured to supply process gas from theone or more process gas supply lines 206 to the downflow manifold body400. The supply manifold header 224 may fluidly communicate with one ormore process gas supply lines 206 (e.g., FIGS. 2B-2D). The one or moreprocess gas supply lines 206 may be coupled to the supply manifoldheader 224, for example, at one or more multiway header fittings 404. Asshown in FIG. 4A, and with reference to FIGS. 2B-2D, a first portion ofa stream of process gas may be supplied from the one or more process gassupply lines 206 by way of a supply manifold header 224, for example, byway of a multiway header fitting 404 coupling the supply manifold header224 to the process gas supply line 206. Additionally, or in thealternative, a second portion of the stream of process gas may besupplied to the crossflow manifold 222, for example, by way of a portionof the process gas supply line 206 extending downstream from the supplymanifold header 224.

An exemplary downflow manifold body 400 may include one or more topdownflow manifold walls 406, one or more bottom downflow manifold walls408, one or more outward downflow manifold walls 410, and/or one or moreinward downflow manifold walls 412. A downflow manifold body 400 mayinclude a top downflow manifold wall 406 configured to be orientedtowards an energy beam system 118, such as towards one or moreirradiation devices 216 and/or one or more monitoring devices 218. Thedownflow manifold body 400 may include one or more attachment points411, such as at the top downflow manifold wall 406, configured to couplethe downflow manifold 210 to one or more components of the energy beamsystem 118. Additionally, or in the alternative, the top downflowmanifold wall 406 may be integrally formed with one or more walls of anenergy beam system. A downflow manifold body 400 may include one or moreoutward downflow manifold walls 410 that define an outer perimeter ofthe downflow manifold body 400. The one or more outward downflowmanifold walls 410 may include attachment points 411 for attaching oneor more irradiation chamber walls 300 to the downflow manifold body 400.Additionally, or in the alternative, the one or more outward downflowmanifold walls 410 may be integrally formed with one or more irradiationchamber walls 300. The downflow manifold body 400 may include one ormore bottom downflow manifold walls 408 configured to be orientedtowards an irradiation plenum 121. A bottom downflow manifold wall 408may define at least a portion of the irradiation chamber 120. Forexample, a bottom downflow manifold wall 408 may provide an upwardboundary to the irradiation plenum 121. Additionally, or in thealternative, the one or more bottom downflow manifold walls 408 may beintegrally formed with at least a portion of the irradiation chamber120, such as with one or more irradiation chamber walls 300.

A supply manifold header 224 may fluidly communicate with a downflowmanifold body 400 at a plurality of locations, such as at a top downflowmanifold wall 406 and/or at one or more outward downflow manifold walls410. The supply manifold header 224 may fluidly communicate with thedownflow manifold body 400 at a plurality of locations distributed aboutone or more outward downflow manifold walls 410. The outward downflowmanifold walls 410 may include end walls and side walls. End walls mayrefer to outward downflow manifold walls 410 that have a length that isless than the average length of the outward downflow manifold walls 410.Side walls may refer to outward downflow manifold walls 410 that have alength that is greater than the average length of the outward downflowmanifold walls 410. The supply manifold header 224 may fluidlycommunicate with one or more outward downflow manifold walls 410configured as end walls of the downflow manifold body 400 and/or withone or more outward downflow manifold walls 410 configured as side wallsof the downflow manifold body 400.

The supply manifold header 224 may include a one or more downflowmanifold distribution elements 209 fluidly communicating with thedownflow manifold body 400, such as at one or more locations about theone or more outward downflow manifold walls 410. A first downflowmanifold distribution element 209 may fluidly communicate with thedownflow manifold body 400 at a first outward downflow manifold wall410, such as a first end wall of the downflow manifold body 400. Thefirst downflow manifold distribution element 209 may fluidly communicatewith a first process gas supply line 206 by way of a first multiwayheader fitting 404. A second downflow manifold distribution element 209may fluidly communicate with the downflow manifold body 400 at a secondoutward downflow manifold wall 410, such as a second end wall of thedownflow manifold body 400. The second downflow manifold distributionelement 209 may fluidly communicate with a second process gas supplyline 206 by way of a second multiway header fitting 404.

A supply manifold header 224 may include a plurality of downflowmanifold distribution elements 209, such as a first downflow manifolddistribution element 209 and a second downflow manifold distributionelement 209, that fluidly communicate with one another, for example, byway of a supply header conjunction element 226. For example, a first endof a supply header conjunction element 226 may fluidly communicate witha first multiway header fitting 404 and a second end of a supply headerconjunction element 226 may fluidly communicate with a second multiwayheader fitting 404. Additionally, or in the alternative, respective endsof a supply header conjunction element 226 may fluidly communicatedirectly with first and second downflow manifold distribution elements209. One or more supply header conjunction elements 226 may allow a flowof process gas to distribute proportionally between respective pathwaysof a downflow manifold 210, such as between respective pathways througha supply manifold header 224 and/or between respective pathways througha downflow manifold body 400.

As shown in FIGS. 4B, 4D, and 4E, a downflow manifold body 400 mayinclude one or mor more downflow manifold pathways 418 disposed therein.The one or more downflow manifold pathways 418 may be defined by the oneor more internal walls of the downflow manifold body 400. A downflowmanifold body 400 may include one or more downflow manifold baffles 420disposed within the one or more downflow manifold pathways 418. Thedownflow manifold pathways 418 and/or the downflow manifold baffles 420may be configured to provide desired fluid properties within the one ormore downflow manifold pathways 418. For example, the downflow manifoldbaffles 420 may encourage process gas to uniformly pressurize the one ormore downflow manifold pathways 418.

The downflow manifold body 400 may include one or more inward downflowmanifold walls 412. The one or more inward downflow manifold walls 412may be oriented parallel or oblique to a longitudinal axis 424 of thedownflow manifold body 400. As shown, for example, in FIGS. 4B-4E, oneor more inward downflow manifold walls 412 may diverge from thelongitudinal axis 424 of the downflow manifold body 400. The inwarddownflow manifold walls 412 may diverge in a proximal direction relativeto the powder bed 227, such that a distance from the longitudinal axis424 to an inward downflow manifold wall 412 increases with increasingproximity to the powder bed 227. A divergence of the one or more inwarddownflow manifold walls 412 may be determined with reference to adivergence angle relative to the longitudinal axis 424 of the downflowmanifold body 400. As shown, for example, in FIG. 2A, the divergenceangle of the one or more inward downflow manifold walls 412 may bedetermined based at least in part on a location of a scan field 212 ofone or more energy beams 214 of an energy beam system 118. Thedivergence angle of the one or more inward downflow manifold walls 412may provide clearance for the one or more energy beams 214 of the energybeam system 118 to access the portion of the build plane 225corresponding to the respective scan field 212, for example, without therespective scan field 212 being interrupted by the one or more inwarddownflow manifold walls 412.

The downflow manifold body 400 may include a plurality of downflowmanifold apertures 422 disposed about one or more walls of the downflowmanifold body 400, such as one or more inward downflow manifold walls412 and/or one or more bottom downflow manifold walls 408. The apertures422 may be in the form of pores, holes, slits, perforations, pinholes,or the like. Process gas flowing through the one or more downflowmanifold pathways 418 may be discharged into the irritation plenum 121and/or the optics plenum 235 through the plurality of downflow manifoldapertures 422. The plurality of downflow manifold apertures 422 may beconfigured and arranged to provide a flow of process gas from thedownflow manifold body 400 into the irradiation plenum 121 and/or theoptics plenum 235 with desired flow characteristics. One or moredownflow manifold baffles 420 may encourage process gas to flowuniformly through the plurality of downflow manifold apertures 422and/or with respect to various regions of the downflow manifold body400, such as with respect to the one or more inward downflow manifoldwalls 412 and/or the one or more bottom downflow manifold walls 408.

The plurality of downflow manifold apertures 422 may have any desiredorientation. The plurality of downflow manifold apertures 422 may beconfigured to provide a flow field with a downward directional vector260, such as a flow field oriented perpendicular to the build plane 225.The flow field may additionally or alternatively oriented perpendicularto the downflow manifold body 400, such as perpendicular to the one ormore bottom downflow manifold walls 408. Additionally, or in thealternative, the plurality of downflow manifold apertures 422 may beconfigured to provide a flow field with a downward directional vector260 oriented parallel to a longitudinal axis 424 of the downflowmanifold body 400.

Additionally, or in the alternative, the plurality of downflow manifoldapertures 422 may be configured to provide a flow field with a lateraldirectional vector 262, such as a flow field oriented parallel to thebuild plane 225. The flow field may additionally or alternativelyoriented parallel to the downflow manifold body 400, such as parallel tothe one or more bottom downflow manifold walls 408. As shown, forexample, in FIGS. 4D and 4E, a directional vector of a flow field fromat least some of the plurality of downflow manifold apertures 422 mayhave any desired orientation, including a downward directional vector260, a lateral directional vector 262 and/or a combination thereof. Atleast some of the plurality of plurality of downflow manifold apertures422 may be oriented parallel or substantially parallel to thelongitudinal axis 424 of the downflow manifold body 400, such as withinabout 10 degrees of parallel to the longitudinal axis 424 of thedownflow manifold body 400, such as within about 5 degrees of parallel,or such as within about 1 degree of parallel to the longitudinal axis424 of the downflow manifold body 400.

A plurality of downflow manifold apertures 422 disposed about the one ormore inward downflow manifold walls 412 may be oriented parallel orsubstantially parallel to the longitudinal axis 424 of the downflowmanifold body 400. Additionally, or in the alternative, a plurality ofdownflow manifold apertures 422 disposed about the one or more bottomdownflow manifold walls 408 may be oriented parallel or substantiallyparallel to the longitudinal axis 424 of the downflow manifold body 400.A majority of the downflow manifold apertures 422 may be orientedparallel or substantially parallel or substantially parallel to thelongitudinal axis of the downflow manifold body 400, and/orsubstantially all of the downflow manifold apertures 422 may be orientedparallel or substantially parallel or substantially parallel to thelongitudinal axis of the downflow manifold body 400. For example, atleast 60%, at least 80%, and/or at least 90% of the downflow manifoldapertures 422 may be oriented parallel or substantially parallel orsubstantially parallel or substantially parallel to the longitudinalaxis of the downflow manifold body 400. Additionally, or in thealternative, at least some of the plurality of plurality of downflowmanifold apertures 422 may be oriented oblique and/or perpendicular tothe longitudinal axis 424 of the downflow manifold body 400. Forexample, a plurality of downflow manifold apertures 422 disposed aboutthe one or more inward downflow manifold walls 412 may be orientedoblique and/or perpendicular to the longitudinal axis 424 of thedownflow manifold body 400. Additionally, or in the alternative, aplurality of downflow manifold apertures 422 oriented perpendicular tothe longitudinal axis 424 of the downflow manifold body 400 may at leastpartially surround the plurality of downflow manifold apertures 422oriented oblique and/or perpendicular to the longitudinal axis 424 ofthe downflow manifold body 400. The plurality of downflow manifoldapertures 422 oriented perpendicular to the longitudinal axis 424 may bedisposed about at the one or more bottom downflow manifold walls 408and/or the one or more inward downflow manifold walls 412.

The size, shape, and/or quantity of the plurality of downflow manifoldapertures 422 may be selected based on the desired flow characteristicsof the process gas provided to the irradiation plenum 121 from thedownflow manifold 210. At least some of the plurality of downflowmanifold apertures 422 may be configured to provide a laminar flow ofprocess gas. Additionally, or in the alternative, at least some of theplurality of downflow manifold apertures 422 may be configured toprovide a turbulent flow of process gas. For example, a downflowmanifold body 400 may include a first plurality of downflow manifoldapertures 422 configure to provide a laminar flow and a second pluralityof downflow manifold apertures 422 configure to provide a turbulentflow.

A downflow manifold 210 may include a downflow manifold body 400 thathas an annular or semiannular configuration. For example, the downflowmanifold 210 shown in FIGS. 4A-4E has a downflow manifold body 400 witha rectangular annular configuration. As another example, a downflowmanifold 210 may include a downflow manifold body 400 that has acurvilinear annular or semiannular configuration. For example, aplurality of downflow manifolds 210 may respectively include a downflowmanifold body 400 that has a semiannular configuration that togetherprovide an annular configuration. Additionally, or in the alternative, adownflow manifold 210 may include a plurality of downflow manifoldbodies 400 that have a semiannular configuration, for example, thattogether provide an annular configuration. The downflow manifold body400 may include one or more inward downflow manifold walls 412 thatdefine at least a portion of an irradiation plenum 121. A downflowmanifold body 400 may include one or more inward downflow manifold walls412 and one or more bottom downflow manifold wall 408, that respectivelydefine a portion of an irradiation plenum 121. Additionally, or in thealternative, at least a portion of one or more bottom downflow manifoldwalls 408 may be configured and arranged externally to an irradiationplenum 121, for example, with only one or more inward downflow manifoldwalls 412 of the downflow manifold body 400 defining a portion of theirradiation plenum 121. However, in other embodiments, a first portionof a bottom downflow manifold wall 408 may define part of theirradiation plenum 121 while a second portion of the bottom downflowmanifold wall 408 may be external to the irradiation plenum 121.

A downflow manifold 210 may include one or more inward downflow manifoldwalls 412 that define an optics plenum 235. The optics plenum 235 mayinclude or refer to a portion of the irradiation plenum 121 adjacent toone or more optics windows 234 that separate one or more opticalelements 233 of an irradiation device 216 from the irradiation plenum121. The optics plenum 235 may include or refer to the portion of theirradiation plenum 121 defined by the one or more inward downflowmanifold walls 412 of the downflow manifold body 400. The optics plenum235 may be defined at least in part by one or more inward downflowmanifold walls 412 that include a plurality of downflow manifoldapertures 422. The plurality of downflow manifold apertures 422 disposedabout the inward downflow manifold walls 412 may supply process gas tothe optics plenum 235. The process gas supplied to the optics plenum 235may prevent contaminants from contacting and/or depositing upon the oneor more optics windows 234 or other components of the energy beam system118 and/or may reduce the quantity of contaminants that contact and/ordeposit upon the one or more optics windows 234 or other components ofthe energy beam system 118 over time.

The plurality of downflow manifold apertures 422 disposed about theinward downflow manifold walls 412 may supply a turbulent flow ofprocess gas to the optics plenum 235, while the plurality of downflowmanifold apertures 422 disposed about the one or more bottom downflowmanifold walls 408 may supply a laminar flow of process gas to theirradiation plenum 121. The turbulent flow of process gas supplied bythe plurality of downflow manifold apertures 422 disposed about theinward downflow manifold walls 412 may provide a turbulent regionadjacent to the one or more optics windows 234. The turbulent region mayoccupy at least a portion of the optics plenum 235. The laminar flow ofprocess gas supplied by the plurality of downflow manifold apertures 422disposed about the one or more bottom downflow manifold walls 408 mayprovide a laminar region within at least a portion of the irradiationplenum 121. The turbulent region may be located within the optics plenum235 defined by the one or more inward downflow manifold walls 412 andthe laminar region may be disposed below the turbulent region. Thelaminar region may provide a flow field that laminarly propagatestowards the crossflow chamber 310. The turbulent region may provide aturbulent crossflow that shields contaminants from entering the opticsplenum 235 and/or that quickly removes contaminants from the opticsplenum 235. Both the laminar region and the turbulent region may bothexhibit turbulent flow, while still providing a similar effect. Forexample, the process gas supplied to the optics plenum 235 may exhibit ahigher degree of turbulence than the process gas supplied to theirradiation plenum 121.

Additionally, or in the alternative, the plurality of downflow manifoldapertures 422 disposed about the inward downflow manifold walls 412 maysupply a laminar flow of process gas to the optics plenum 235, while theplurality of downflow manifold apertures 422 disposed about the one ormore bottom downflow manifold walls 408 may supply a turbulent flow ofprocess gas to the irradiation plenum 121.

The laminar flow of process gas supplied by the plurality of downflowmanifold apertures 422 disposed about the inward downflow manifold walls412 may provide a laminar region within the optics plenum 235 and/or astagnant region adjacent to the one or more optics windows 234. Thelaminar region and/or the stagnant region may occupy at least a portionof the optics plenum 235. The turbulent flow of process gas supplied bythe plurality of downflow manifold apertures 422 disposed about the oneor more bottom downflow manifold walls 408 may provide a turbulentregion within at least a portion of the irradiation plenum 121. Thelaminar region and/or the stagnant region may be located within theoptics plenum 235 defined by the one or more inward downflow manifoldwalls 412 and the turbulent region may be disposed below the laminarregion and/or the stagnant region. The laminar region and/or theturbulent region may provide a flow field that propagates towards thecrossflow chamber 310. The stagnant region may shield contaminants fromentering the optics plenum 235 and/or may cause contaminants to fall outof the optics plenum 235 by vulture of flow stagnation within the opticsplenum 235. Both the laminar region and the turbulent region may bothexhibit turbulent flow and/or laminar flow, while still providing asimilar effect. For example, the process gas supplied to the opticsplenum 235 may exhibit a lower degree of flow than the process gassupplied to the irradiation plenum 121.

Now turning to FIGS. 5A and 5B, exemplary crossflow manifolds 222 willbe further described. A crossflow manifold 222 may be in fluidcommunication with one or more process gas supply lines 206. Thecrossflow manifold 222 may be configured to provide a crossflow ofprocess gas to an irradiation plenum 121 defined by an irradiationchamber 120, and/or to a crossflow plenum 311 defined by a crossflowchamber 310. A crossflow manifold 222 may include one or more crossflowmanifold bodies 500. For example, as shown in FIGS. 5A and 5B, acrossflow manifold 222 may include a plurality of crossflow manifoldbodies 500 configured and arranged along a width of the crossflowmanifold 222. The plurality of crossflow manifold bodies 500 may becoupled to one another. Additionally, or in the alternative, a pluralityof crossflow manifold bodies 500 may define respective portions of anintegrally formed crossflow manifold 222.

A crossflow manifold body 500 may be configured to modify across-sectional surface area of a process gas flow field flowing intothe crossflow manifold 222 and through the crossflow manifold body 500.A flow field flowing into the crossflow manifold body 500 may have acircular cross-sectional profile, corresponding, for example, to aprocess gas supply line 206. A flow field discharged from the crossflowmanifold body 500 may have an elongate cross-sectional profile,corresponding, for example, to a crossflow plenum 311 defined by acrossflow chamber 310. Additionally, or in the alternative, a flow fieldflowing into the crossflow manifold body 500 may include a downwarddirectional vector 260, corresponding, for example to an orientation ofa process gas supply line 206. A flow field discharged from thecrossflow manifold body 500 may include a lateral flow field with alateral directional vector 262, corresponding, for example, to anorientation of a crossflow plenum 311 defined by a crossflow chamber310. The flow of process gas flowing through the crossflow manifold body500 may be conformed to an elongate flow field. The lateral flow field,such as the elongate flow field, may flow laterally across the crossflowplenum 311 defined by a crossflow chamber 310. A crossflow manifold body500 may conform one or more circular cross-sectional flow fields with adownward directional vector 260 into one or more elongate flow fieldswith a lateral directional vector 262.

A crossflow manifold 222 and/or a crossflow manifold body 500 mayinclude one or more crossflow manifold inlets 502 and one or morecrossflow manifold outlets 504. The crossflow manifold 222 may includeone more crossflow manifold pathways 506 defined at least in part by theone or more crossflow manifold bodies 500. One or more crossflowmanifold pathway walls 508 may define at least a portion of a pluralityof crossflow manifold pathways 506. The one or more crossflow manifoldpathway walls 508 may be disposed within the crossflow manifold body500, and/or the one or more crossflow manifold pathway walls 508 may beintegrally formed with the crossflow manifold body 500 as a singlecomponent.

Process gas entering the one or more crossflow manifold inlets 502 mayflow through the one more crossflow manifold pathways 506 and exit thecrossflow manifold 222 at the one or more crossflow manifold outlets504. As shown, for example, in FIGS. 5A and 5B, a crossflow manifold mayinclude a plurality of crossflow manifold inlets 502 and a commoncrossflow manifold outlet 504. Respective ones of a plurality ofcrossflow manifold inlets 502 may correspond to respective ones of aplurality of crossflow manifold bodies 500. The plurality of crossflowmanifold bodies 500 may have a common crossflow manifold outlet 504. Oneor more crossflow manifold outlets 504 may be configured to discharge alateral flow field of process gas that has an elongate cross-sectionalsurface area. The crossflow manifold body 500 may have a shape thatconforms the cross-sectional surface area of a flow field from an inletcross-sectional surface area, corresponding to one or more crossflowmanifold inlets 502, to an outlet cross-sectional surface area,corresponding to one or more crossflow manifold outlets 504. As shown,the one or more crossflow manifold inlets 502 may have an ellipticalcross-sectional profile, such as a circular cross-sectional profile.However, crossflow manifold inlets 502 with other cross-sectionalprofiles are also contemplated, including crossflow manifold inlets 502with rectangular or polygonal cross-sectional profiles. The one or morecrossflow manifold outlets 504 may have an elongate cross-sectionalprofile. As shown, the elongate cross-sectional surface area of acrossflow manifold outlet 504 may have a rectangular cross-sectionalprofile; however, other cross-sectional profiles are also contemplated,including curvilinear cross-sectional profiles, such as an ellipticalcross-sectional profiles.

A crossflow manifold outlet 504 may discharge a flow of process gassupplied from a plurality of crossflow manifold inlets 502.Additionally, or in the alternative, a crossflow manifold outlet 504 maydischarge a flow of process gas from a plurality of crossflow manifoldpathways 506. The number of crossflow manifold inlets 502 may exceed thenumber of crossflow manifold outlets 504 by at least one. A crossflowmanifold 222 may include a plurality of crossflow manifold inlets 502and one or more crossflow manifold outlets 504, such as from two to sixcrossflow manifold inlets 502 and from one to three crossflow manifoldoutlets 504, such as two, three, four, five, or six crossflow manifoldinlets 502, and one, two, or three crossflow manifold outlets 504. Asshown in FIGS. 5A and 5B, a crossflow manifold 222 may include twocrossflow manifold inlets 502 and one crossflow manifold outlet 504.

The configuration and arrangement of the crossflow manifold body 500 maybe determined at least in part to provide a lateral flow field withdesired flow characteristics. The crossflow manifold body 500, the oneor more crossflow manifold pathways 506, and/or the one or morecrossflow manifold pathway walls 508 may be configured to modify across-sectional profile of a flow field. The cross-sectional profile ofthe flow field may be modified with respect to geometry and/or surfacearea. The cross-sectional profile of the flow field may be modified froman elliptical cross-sectional profile, such as a circularcross-sectional profile, at the one or more crossflow manifold inlets502, to an elongate cross-sectional profile, such as a rectangularcross-sectional profile, at the crossflow manifold outlet 504.Additionally, or in the alternative, the crossflow manifold body 500,the one or more crossflow manifold pathways 506, and/or the one or morecrossflow manifold pathway walls 508 may be configured to modify adirectional vector of the flow field. For example, the directionalvector of the flow field may be modified from a downward directionalvector 260 at the one or more crossflow manifold inlets 502 to a lateraldirectional vector 262 at the one or more crossflow manifold outlets504.

The crossflow manifold body 500 may include one more crossflow manifoldpathways 506 that have a curvilinear profile. The curvilinear profile ofthe one more crossflow manifold pathways 506 may facilitate a change inone or more geometric dimensions of the one more crossflow manifoldpathways 506 from the one or more crossflow manifold inlets 502 to theone or more one or more crossflow manifold outlets 504. Additionally, orin the alternative, the curvilinear profile of the one more crossflowmanifold pathways 506 may facilitate a change in the directional vectorof the flow field of process gas from the one or more crossflow manifoldinlets 502 to the one or more one or more crossflow manifold outlets504. The crossflow manifold body 500 may expand transversely relative toa longitudinal axis 510 of one or more crossflow manifold inlets 502and/or relative to a lateral axis 512 of one or more crossflow manifoldoutlets 504. The curvilinear profile of the one more crossflow manifoldpathways 506 may facilitate a change in one or more geometricdimensions, and/or a change in the directional vector of the flow fieldof process gas from the one or more crossflow manifold inlets 502 to theone or more one or more crossflow manifold outlets 504, withoutsignificantly disrupting a boundary layer air within the crossflowmanifold body 500, such as within the respective crossflow manifoldpathways 506. For example, the curvilinear profile of the one or morecrossflow manifold pathways 506 may avoid form drag and flow separation,for example, by creating counter-rotating vortices which draw processgas further into the respective crossflow manifold pathways 506. Atleast a portion of the curvilinear profile crossflow manifold body 500may emulate at least a portion of an NACA air duct.

The crossflow manifold body 500 may include a transverse expansionregion 514 and/or a lateral translation region 516. The transverseexpansion region 514 may be located downstream from a crossflow manifoldinlet 502. The transverse expansion region 514 includes a region of thecrossflow manifold body 500 that exhibits a transverse expansionrelative to the longitudinal axis 510 of one or more crossflow manifoldinlets 502 and/or relative to a lateral axis 512 of one or morecrossflow manifold outlets 504. At least some of a plurality ofcrossflow manifold pathways 506 may exhibit a transverse expansion inthe transverse expansion region 514 described with reference to thecrossflow manifold body 500. The rate of transverse expansion may differas between respective ones of the plurality of crossflow manifoldpathways 506. One or more of the plurality of crossflow manifoldpathways 506 need not exhibit a transverse expansion while at least someof the plurality of crossflow manifold pathways 506 exhibit a transverseexpansion within the transverse expansion region 514.

The lateral translation region 516 may be located downstream from atransverse expansion region 514. Additionally, or in the alternative,the lateral translation region 516 may be located upstream from acrossflow manifold outlet 504. The lateral translation region 516includes a region of the crossflow manifold body 500 that exhibits alateral translation in the axial orientation of the crossflow manifoldbody 500, for example, relative to the longitudinal axis 510 of one ormore crossflow manifold inlets 502 and/or relative to a lateral axis 512of one or more crossflow manifold outlets 504. The axial orientation ofthe crossflow manifold body 500 may be aligned with the longitudinalaxis 510, for example, at the one or more crossflow manifold inlets 502.The axial orientation of the crossflow manifold body 500 may be alignedwith the lateral axis 512, for example, at the one or more crossflowmanifold outlets 504. The alignment of the axial orientation of thecrossflow manifold body 500 may transition laterally within the lateraltranslation region 516, for example, providing increasing alignment withthe lateral axis 512 and/or decreasing alignment with the longitudinalaxis 510. The lateral translation region may include a translation ofthe axial orientation of the crossflow manifold body 500 from beingaligned with the longitudinal axis 510 to being aligned with the lateralaxis 512. However, the crossflow manifold body 500 need not be alignedprecisely with the longitudinal axis 510 and/or the crossflow manifoldbody 500 need not be aligned precisely with the lateral axis 512. Atleast some of a plurality of crossflow manifold pathways 506 may exhibita lateral translation in the respective axial orientation within in thelateral translation region 516 as described with reference to thecrossflow manifold body 500. The rate of lateral translation may differas between respective ones of the plurality of crossflow manifoldpathways 506.

At least a portion of the transverse expansion region 514 may overlapwith at least a portion of the lateral translation region 516.Additionally, or in the alternative, at least a portion of thetransverse expansion region 514 may be separated from at least a portionof the lateral translation region 516. For example, a crossflow manifoldbody 500 may include a longitudinal extension region 518 disposedbetween at least a portion of the transverse expansion region 514 and atleast a portion of the lateral translation region 516. The longitudinalextension region 518 represents a region of the crossflow manifold body500 that exhibits a longitudinal extension relative to the longitudinalaxis 510 of one or more crossflow manifold inlets 502. At least some ofa plurality of crossflow manifold pathways 506 may exhibit alongitudinal extension in the longitudinal extension region 518described with reference to the crossflow manifold body 500. The degreeof longitudinal extension region 518 may differ as between respectiveones of the plurality of crossflow manifold pathways 506. One or more ofthe plurality of crossflow manifold pathways 506 need not exhibit alongitudinal extension while at least some of the plurality of crossflowmanifold pathways 506 exhibit a longitudinal extension within thelongitudinal extension region 518.

A crossflow manifold body 500 may include a lateral profiling region520. The lateral profiling region 520 represents a region of thecrossflow manifold body 500 that exhibits a lateral change incross-sectional profile, for example, relative to the cross-sectionalprofile of the one or more crossflow manifold inlets 502. For example,the cross-sectional profile of the crossflow manifold body 500 maychange laterally from a cross-sectional profile at the one or morecrossflow manifold inlets 502 to a cross-sectional profile at the one ormore crossflow manifold outlets 504. At least some of a plurality ofcrossflow manifold pathways 506 may exhibit a lateral change incross-sectional profile in the lateral profiling region 520 describedwith reference to the crossflow manifold body 500. The rate of change inthe lateral cross-sectional profile may differ as between respectiveones of the plurality of crossflow manifold pathways 506. One or more ofthe plurality of crossflow manifold pathways 506 need not exhibit alateral change in cross-sectional profile while at least some of theplurality of crossflow manifold pathways 506 exhibit a lateral change incross-sectional profile within the lateral profiling region 520.

The lateral profiling region 520 may overlap at least a portion of thetransverse expansion region 514 and/or at least a portion of the lateraltranslation region 516. Additionally, or in the alternative, at least aportion of the lateral profiling region 520 may be separated from atleast a portion of the transverse expansion region 514 and/or from atleast a portion of the lateral translation region 516. The lateralprofiling region 520 may overlap at least a portion of the longitudinalextension region 518. Additionally, or in the alternative, at least aportion of the lateral profiling region 520 may be separated from atleast a portion of the longitudinal extension region 518. Thelongitudinal extension region 518 may be disposed between at least aportion of the lateral profiling region 520 and at least a portion ofthe lateral translation region 516. The longitudinal extension region518 may exhibit a longitudinal extension relative to the longitudinalaxis 510 of one or more crossflow manifold inlets 502, without a lateralchange in cross-sectional profile such as may be exhibited in thelateral profiling region 520. At least some of a plurality of crossflowmanifold pathways 506 may exhibit a longitudinal extension in thelongitudinal extension region 518, without a lateral change incross-sectional profile such as may be exhibited in the lateralprofiling region 520. One or more of the plurality of crossflow manifoldpathways 506 need not exhibit a lateral change in cross-sectionalprofile, while at least some of the plurality of crossflow manifoldpathways 506 exhibit a lateral change in cross-sectional profile withinthe lateral profiling region 520.

One or more geometric properties of the one or more crossflow manifoldpathways 506, and/or of the cross-sectional profile of the flow field,may be modified at one or more regions from the one or more crossflowmanifold inlets 502 to the one or more crossflow manifold outlets 504.For example, an elliptical cross-sectional profile, such as a circularcross-sectional profile, at the one or more crossflow manifold inlets502 may be confirmed to an elongate cross-sectional profile, such as arectangular cross-sectional profile, at the one or more crossflowmanifold outlets 504. Additionally, or in the alternative, thecross-sectional surface area of the cross-sectional profile of the flowfield may be modified as between the one or more crossflow manifoldinlets 502 and the one or more crossflow manifold outlets 504. Invarious embodiments, the cross-sectional surface area may be increased,decreased, and/or maintained. The cross-sectional surface area of theflow field may remain substantially equivalent as between the one ormore crossflow manifold inlets 502 and the one or more crossflowmanifold outlets 504. Additionally, or in the alternative, thecross-sectional surface area may be increased from the one or morecrossflow manifold inlets 502 to the one or more crossflow manifoldoutlets 504, for example, for example, in an amount of from about 5% toabout 90%, such as from about 10% to about 80%, or such as from about25% to about 75%. The increasing cross-sectional surface area mayprovide a pressure reduction and/or a decrease in velocity of the flowfield, which may result in a lateral flow field with desired flowcharacteristics. Additionally, or in the alternative, thecross-sectional surface area may be decreased from the one or morecrossflow manifold inlets 502 to the one or more crossflow manifoldoutlets 504, for example, in an amount of from about 5% to about 90%,such as from about 10% to about 80%, or such as from about 25% to about75%. The decreasing cross-sectional surface area may provide a pressureincrease and/or an increase in velocity of the flow field, which mayresult in a lateral flow field with desired flow characteristics. Thecross-sectional surface area of the one or more crossflow manifoldinlets 502 and the cross-sectional surface area of the one or morecrossflow manifold outlets 504 may be within about 25% of one another,such as within about 10% of one another, such as within about 5% of oneanother, or such as within about 1% of one another. Additionally, or inthe alternative, the cross-sectional surface area of the one or morecrossflow manifold inlets 502 and the cross-sectional surface area ofthe one or more crossflow manifold outlets 504 may differ from oneanother by up to 125%, such as up to 100%, such as up to 50%, such as upto 25%. Such a pressure increase and/or decrease may be determined frompressure measurements obtained with one or more pressure sensorsconfigured to determine an upstream pressure and a downstream pressure,and or a pressure differential. By way of example, such pressure orpressure differential may be determined by a differential pressuresensor.

The one or more crossflow manifold outlets 504 may have a width and aheight that are proportioned such that the width exceeds the height, forexample, by a factor of from about 10:1 to 100:1, such as from about10:1 to about 50:1, or such as from about 10:1 to about 20:1. A width ofthe lateral flow field of process gas discharged from the one or morecrossflow manifold outlets 504 may exceed a height of the lateral flowfield. For example, a ratio of the width of the lateral flow field tothe height of the lateral flow field may be from about 10:1 to 100:1,such as from about 10:1 to about 50:1, or such as from about 10:1 toabout 20:1.

In addition, or in the alternative, to changing a cross-sectionalprofile of a flow field, the crossflow manifold body 500 may beconfigured to change a directional vector of the flow field. Thecrossflow manifold body 500 may include one or more crossflow manifoldinlets 502 respectively fluidly communicating with a process gas supplyline 206. The crossflow manifold body 500 may be configured to change adirection vector of the flow field at the one or more crossflow manifoldinlets 502 to a directional vector at the one or more crossflow manifoldoutlets 504. The crossflow manifold body 500 may modify a downwarddirectional vector 260 at the one or more crossflow manifold inlets 502to a lateral directional vector 262 at the one or more crossflowmanifold outlets 504. The crossflow manifold body 500 may provide alaterally accelerating directional vector 264. The modification to thedirectional vector from the one or more crossflow manifold inlets 502 tothe one or more crossflow manifold outlets 504 may be about 90 degrees,such as from about 80 degrees to about 100 degrees, such as from about70 degrees to about 90 degrees, or such as from about 85 to about 95degrees. Additionally, or in the alternative, the directional vector ofa flow field may be modified from the one or more crossflow manifoldinlets 502 to the one or more crossflow manifold outlets 504 in anamount of from about 10 degrees to about 100 degrees, such as from about30 degrees to about 90 degrees, such as from about 60 degrees to about90 degrees, or from about 10 degrees to about 45 degrees.

A longitudinal axis 510 of one or more crossflow manifold inlets 502 maybe oriented perpendicular to the build plane 225, or substantiallyperpendicular to the build plane 225, such as at about 90 degreesrelative to the build plane 225, such as from about 80 to 100 degreesrelative to the build plane 225, or such as from about 85 to 95 degreesrelative to the build plane. Additionally, or in the alternative, alongitudinal axis 510 of one or more crossflow manifold inlets 502 maybe oriented parallel or substantially parallel to the build plane 225,such as within about 10 degrees of parallel to the build plane 225, suchas within about 5 degrees of parallel to the build plane 225, or withinabout 1 degree of parallel to the build plane 225. Additionally, or inthe alternative, a longitudinal axis 510 of one or more crossflowmanifold inlets 502 may be oriented oblique to the build plane 225, suchas from about 5 degrees to about 85 degrees, such as from about 30degrees to about 85, such as from about 60 degrees to about 80 degrees,or such as from about 10 degrees to about 45 degrees relative to thebuild plane 225.

In addition, or in the alternative, to an orientation of thelongitudinal axis 510 of one or more crossflow manifold inlets 502relative to the build plane 225, the longitudinal axis 510 of one ormore crossflow manifold inlets 502 may be oriented may be orientedparallel or substantially parallel to the longitudinal axis 424 of thedownflow manifold body 400, such as such as within about 10 degrees ofthe longitudinal axis 424 of the downflow manifold body 400, such aswithin about 5 degrees of the longitudinal axis 424 of the downflowmanifold body 400, or such as within about 1 degree of the longitudinalaxis 424 of the downflow manifold body 400. Additionally, or in thealternative, the longitudinal axis 510 of one or more crossflow manifoldinlets 502 may be oriented oblique to the longitudinal axis 424 of thedownflow manifold body 400, such as from about 5 degrees to about 85degrees relative to the longitudinal axis 424 of the downflow manifoldbody 400, such as from about 30 degrees to about 85, such as from about60 degrees to about 80 degrees, such as from about 10 degrees to about45 degrees relative to the longitudinal axis 424 of the downflowmanifold body 400.

Additionally, or in the alternative, the longitudinal axis 510 of one ormore crossflow manifold inlets 502 may be oriented parallel orsubstantially parallel to the longitudinal axis 316 of the irradiationchamber 120 and/or crossflow chamber 310, such as within about 10degrees of parallel to the longitudinal axis 316 of the irradiationchamber 120 and/or crossflow chamber 310, such as within about 5 degreesof parallel to the longitudinal axis 316 of the irradiation chamber 120and/or crossflow chamber 310, or within about 1 degree of parallel tothe longitudinal axis 316 of the irradiation chamber 120 and/orcrossflow chamber 310. Additionally, or in the alternative, thelongitudinal axis 510 of one or more crossflow manifold inlets 502 maybe oriented oblique to the longitudinal axis 316 of the irradiationchamber 120 and/or crossflow chamber 310, such as from about 5 degreesto about 85 degrees relative to the longitudinal axis 316 of theirradiation chamber 120 and/or crossflow chamber 310, such as from about30 degrees to about 85, such as from about 60 degrees to about 80degrees, such as from about 10 degrees to about 45 degrees relative tothe longitudinal axis 316 of the irradiation chamber 120 and/orcrossflow chamber 310. Additionally, or in the alternative, thelongitudinal axis 510 of one or more crossflow manifold inlets 502 maybe oriented perpendicular or substantially perpendicular to thelongitudinal axis 316 of the irradiation chamber 120 and/or crossflowchamber 310, such as within about 10 degrees of perpendicular to thelongitudinal axis 316 of the irradiation chamber 120 and/or crossflowchamber 310, such as within about 5 degrees of perpendicular to thelongitudinal axis 316 of the irradiation chamber 120 and/or crossflowchamber 310, or within about 1 degree of perpendicular to thelongitudinal axis 316 of the irradiation chamber 120 and/or crossflowchamber 310.

A lateral axis 512 of the one or more crossflow manifold outlets 504 maybe oriented parallel to the build plane 225, or substantially parallelto the build plane 225, such as at about 0 degrees relative to the buildplane 225, such as within about 10 degrees of parallel to the buildplane 225, such as within about 5 degrees of parallel to the build plane225, or within about 1 degree of parallel to the build plane 225. Theone or more crossflow manifold outlets 504 may discharge a lateral flowfield with a lateral directional vector 262 oriented parallel to thebuild plane 225, or substantially parallel to the build plane 225, suchas at about 0 degrees relative to the build plane 225, such as withinabout 10 degrees of parallel to the build plane 225, such as withinabout 5 degrees of parallel to the build plane 225, or within about 1degree of parallel to the build plane 225. The lateral directionalvector 262 may be oriented oblique and/or upward relative to the buildplane 225, such as from about 1 degree to about 20 degrees obliqueand/or upward relative to the build plane 225, such as from about 1degree to about 10 degrees oblique and/or upward relative to the buildplane 225, or such as from about 1 degree to about 5 degrees obliqueand/or upward relative to the build plane 225.

Referring now to FIGS. 6A-6F, exemplary crossflow manifold inlets 502will be further described. As shown in FIG. 6A, one or more crossflowmanifold pathway walls 508 may be disposed within a crossflow manifoldinlet 502. Additionally, or in the alternative, one or more crossflowmanifold pathway walls 508 may be located within the crossflow manifoldbody 500 downstream from the crossflow manifold inlet 502. At least someof the crossflow manifold pathway walls 508, and/or at least a portionof a respective crossflow manifold pathway walls 508 may be orientedparallel to a lateral axis 512 of the crossflow manifold body 500, orsubstantially parallel to the lateral axis 512 of the crossflow manifoldbody 500, such as within about 10 degrees of parallel to the lateralaxis 512 of the crossflow manifold body 500, such as within about 5degrees of parallel to the lateral axis 512 of the crossflow manifoldbody 500, or within about 1 degree of parallel to the lateral axis 512of the crossflow manifold body 500. However, additionally, or in thealternative, at least some of the crossflow manifold pathway walls 508,and/or at least a portion of a respective crossflow manifold pathwaywalls 508 may be oriented oblique and/or perpendicular to the lateralaxis 512 of the crossflow manifold body 500. A plurality of crossflowmanifold pathway walls 508 may have a spacing determined based at leastin part on a desired cross-sectional surface area of respectivecrossflow manifold pathways 506. A plurality of crossflow manifoldpathway walls 508 may be spaced relative to one another so as to providea uniformly sized cross-sectional surface area as between respectivecrossflow manifold pathways 506. The uniformly sized cross-sectionalsurface areas may differ in cross-sectional profile, for example,corresponding at least in part to the cross-sectional profile of thecrossflow manifold inlet 502.

As shown in FIGS. 6B-6F, a crossflow manifold inlet 502 may include,and/or may be configured to receive, one or more inlet flow conditioners600. An inlet flow conditioner 600 may include a lattice 602 defining aplurality of inlet flow conditioning channels 604. The plurality ofinlet flow conditioning channels 604 may be configured and arranged inan array, such as an array of inlet flow conditioning channels 604. Theinlet flow conditioning channels 604 may have any desired geometry.Suitable geometry for the plurality and/or array of inlet flowconditioning channels 604 may be selected based at least in part on theeffect of the inlet flow conditioner 600 on flow of process gas throughthe crossflow manifold 222. For example, as shown, an inlet flowconditioner 600 may include a lattice 602 defining a plurality and/or anarray of inlet flow conditioning channels 604 that have a hexagonalcross section. Additionally, or in the alternative, the plurality and/orarray of inlet flow conditioning channels 604 may have any other desiredgeometric configuration, including a polygonal, elliptical, and/orcurvilinear configuration.

As shown in FIGS. 6C and 6D, at least some of the plurality of inletflow conditioning channels 604 may be oriented parallel to alongitudinal axis 510 of the crossflow manifold inlet 502. Additionally,or in the alternative, as shown in FIGS. 6E and 6F, at least some of theplurality of inlet flow conditioning channels 604 may be orientedoblique to the longitudinal axis 510 of the crossflow manifold inlet502. For example, at least some of the plurality of inlet flowconditioning channels 604 may have an orientation that diverges from thelongitudinal axis 510 of the crossflow manifold inlet 502. The obliquelyoriented and/or converging inlet flow conditioning channels 604 may havean angle relative to the longitudinal axis 510 of the crossflow manifoldinlet 502 of from about 0.1 degrees to about 20 degrees, such as fromabout 1 degree to about 10 degrees, or from about 0.1 degrees to about 5degrees.

At least some of the plurality of inlet flow conditioning channels 604may be oriented relative to a normal line perpendicular to a tangent ofa curvilinear plane. For example, the curvilinear plane may correspondto a portion of a sphere, an ovoid, or the like. The orientation of atleast some of the inlet flow conditioning channels 604 may at leastpartially correspond to an orientation of the respective crossflowmanifold pathways 506 downstream from the inlet flow conditioningchannels 604. For example, a longitudinal axis of at least some of theinlet flow conditioning channels 604 may be parallel, or substantiallyparallel, to a longitudinal axis of a respectively correspondingcrossflow manifold pathway 506 determined, for example, about a regionof the crossflow manifold inlet 502 and/or crossflow manifold body 500adjacently downstream from the inlet flow conditioner 600 and/or therespectively oriented inlet flow conditioning channels 604. By way ofexample, a longitudinal axis of at least some of the inlet flowconditioning channels 604 may be within about 10 degrees of alongitudinal axis of a respectively corresponding crossflow manifoldpathway 506, such as within about 5 degrees, or such as within about 1degree of a longitudinal axis of a respectively corresponding crossflowmanifold pathway 506, determined, for example, about a region of thecrossflow manifold inlet 502 and/or crossflow manifold body 500adjacently downstream from the inlet flow conditioner 600 and/or therespectively oriented inlet flow conditioning channels 604.

An inlet flow conditioner 600 may include one or more featuresconfigured to fit the inlet flow conditioner 600 to a crossflow manifoldinlet 502. For example, as shown in FIGS. 6C-6F, the inlet flowconditioner 600 may have an outward circumference that corresponds to aninward circumference of the crossflow manifold inlet 502. The inlet flowconditioner 600 may be removably and/or fixedly inserted into thecrossflow manifold inlet 502. For example, the inlet flow conditioner600 may exhibit a snap-fit or press-fit characteristic when insertedinto an inward circumference of a crossflow manifold inlet 502. Theinlet flow conditioner 600 may include one or more alignment tabs 606.The one or more alignment tabs 606 may fit with a corresponding one ormore alignment slots 608 in the crossflow manifold inlet 502.Additionally, or in the alternative, one or more alignment tabs 606 maybe provided as part of the crossflow manifold inlet 502, and the inletflow conditioner 600 may include a corresponding one or more alignmentslots 608. Additionally, or in the alternative, an inlet flowconditioner 600 may be integrally formed as part of the crossflowmanifold body 500 defining the crossflow manifold inlet 502.

Referring now to FIGS. 7A-7C, and with further reference to FIG. 5A, acrossflow manifold 222 may include an outlet flow conditioner 700disposed in a crossflow manifold outlet 504. The crossflow manifoldoutlet may be configured to receive the outlet flow conditioner 700.Exemplary outlet flow conditioners 700 are shown in FIGS. 7A-7C. Asshown in FIG. 5A, a crossflow manifold body 500 and/or a crossflowmanifold outlet 504 may include one or more crossflow manifold sidewall522 that respectively have one or more outlet flow conditioner accessports 524. One or more crossflow manifold bodies 500 may include one ormore outlet flow conditioner slots 526 extending transversely across atleast a portion of the one or more crossflow manifold bodies 500. Arespective outlet flow conditioner access ports 524 may provide accessto the one or more outlet flow conditioner slots 526. The one or moreoutlet flow conditioner slots 526 may extending transversely across theone or more crossflow manifold bodies adjacent to and/or upstream fromthe crossflow manifold outlet 504. One or more outlet flow conditioners700 may be removably inserted through the respective outlet flowconditioner access ports 524 and transversely into a correspondingoutlet flow conditioner slot 526. Additionally, or in the alternative,an outlet flow conditioner 700 may be integrally formed as part of thecrossflow manifold outlet 504 and/or as part of the crossflow manifoldbody 500.

As shown in FIGS. 7A-7C, an outlet flow conditioner 700 may include alattice 702 defining a plurality of outlet flow conditioning channels704. The plurality of outlet flow conditioning channels 704 may beconfigured and arranged in an array, such as an array of outlet flowconditioning channels 704. The outlet flow conditioning channels 704 mayhave any desired geometry. Suitable geometry for the plurality and/orarray of outlet flow conditioning channels 704 may be selected based atleast in part on the effect of the outlet flow conditioner 700 on flowof process gas discharging from the crossflow manifold outlet 504. Forexample, as shown, an outlet flow conditioner 700 may include a lattice702 defining a plurality and/or an array of outlet flow conditioningchannels 704 that have a hexagonal cross section. Additionally, or inthe alternative, the plurality and/or array of outlet flow conditioningchannels 704 may have any other desired geometric configuration,including a polygonal, elliptical, and/or curvilinear configuration.

As shown in FIG. 7A, at least some of the plurality of outlet flowconditioning channels 704 may be oriented parallel to a lateral axis 512of the crossflow manifold outlet 504. Additionally, or in thealternative, as shown in FIGS. 7B and 7C, at least some of the pluralityof outlet flow conditioning channels 704 may be oriented oblique to thelateral axis 512 of the crossflow manifold outlet 504. For example, atleast some of the plurality of outlet flow conditioning channels 704 mayhave an orientation that converges towards the lateral axis 512 of thecrossflow manifold outlet 504 in a direction of the flow of process gasthrough the outlet flow conditioning channels 704. The obliquelyoriented and/or converging outlet flow conditioning channels 704 mayhave an angle relative to the lateral axis 512 of the crossflow manifoldoutlet 504 of from about 0.1 degrees to about 20 degrees, such as fromabout 1 degree to about 10 degrees, or from about 0.1 degrees to about 5degrees. An oblique and/or converging orientation of the outlet flowconditioning channels 704 may provide a pressure increase and/or anincrease in velocity of a lateral flow field discharging from thecrossflow manifold outlet 504, providing desired flow characteristics.

At least some of the plurality of outlet flow conditioning channels 704may be oriented relative to a normal line perpendicular to a tangent ofa curvilinear plane. For example, the curvilinear plane may correspondto a portion of a sphere, an ovoid, or the like. The orientation of atleast some of the outlet flow conditioning channels 704 may at leastpartially correspond to a desired configuration of a lateral flow fielddischarging from the crossflow manifold outlet 504. For example,orientation of the outlet flow conditioning channels 704 may beconfigured to provide a converging lateral flow field discharging fromthe crossflow manifold outlet 504. A converging lateral flow field mayprovide a uniform crossflow of process gas, such as from a crossflowmanifold 222 to a return manifold 204. Additionally, or in thealternative, a converging lateral flow field may prevent or reduce thetendency for process gas to escape from beneath the crossflow walls 314of the crossflow chamber 310. By way of example, at least some of theoutlet flow conditioning channels 704 may be oriented along a normalline perpendicular to a tangent of a curvilinear plane in which thelength of the outlet flow conditioner 700 transverse to the lateral axis512 of the crossflow manifold outlet 504 corresponds to a chord lengthof an arc extending transversely across the curvilinear plane, such asan arc. Additionally, or in the alternative, a width of the outlet flowconditioner 700 may correspond to a sagitta of the arc extendingtransversely across the curvilinear plane, such as an arc. Additionally,or in the alternative, at least some of the outlet flow conditioningchannels 704 may be oriented along normal lines that intersect at apoint corresponding to a radius of the arc extending transversely acrossthe curvilinear plane. The arc length may be from about 1 degree toabout 90 degrees, such as from about 5 degrees to about 60 degrees, suchas from about 10 degrees to about 30 degrees.

Referring again to FIG. 5A, a crossflow manifold body 500 and/or acrossflow manifold outlet 504 may include one or more featuresconfigured to retain the one or more outlet flow conditioners 700 inrespective outlet flow conditioner slots 526. For example, the crossflowmanifold body 500 and/or the crossflow manifold outlet 504 may have oneor more outlet ridges 528 that retain respective ones of the one or moreoutlet flow conditioners 700. An outlet flow conditioner 700 may have across-sectional profile configured to mate with a cross-sectionalprofile of an outlet flow conditioner access port 524 and/or an outletflow conditioner slot 526. For example, as shown, an outlet flowconditioner access port 524 and/or an outlet flow conditioner slot 526may have a “D” shaped cross-sectional profile, and an outlet flowconditioner 700 may have a corresponding “D” shape. Additionally, or inthe alternative, an outlet flow conditioner 700 may include one or morealignment tabs similar to those described with reference to the inletflow conditioners 600. The one or more alignment tabs 606 may fit with acorresponding one or more alignment slots 608 in the crossflow manifoldoutlet 504.

Now turning to FIGS. 8A-8B, exemplary return manifolds 204 will bedescribed. A return manifold 204 may be in fluid communication with oneor more process gas evacuation lines 208. The return manifold 204 may beconfigured to receive and/or evacuate a flow of process gas from anirradiation plenum 121 defined by an irradiation chamber 120.Additionally, or in the alternative, the return manifold 204 may beconfigured to receive and/or evacuate a flow of process gas from acrossflow plenum 311 defined by a crossflow chamber 310 and/or from adownflow plenum 309 defined by a downflow chamber 308. For example, areturn manifold 204 may receive and/or evacuate a flow of process gasfrom a crossflow manifold 222 and/or a flow of process gas from adownflow manifold 210. A return manifold 204 may include one or morereturn manifold bodies 800. For example, as shown in FIGS. 8A and 8B, areturn manifold body 800 may include a plurality of return manifoldbodies 800 configured and arranged along a width of the return manifold204. The plurality of return manifold bodies 800 may be coupled to oneanother. Additionally, or in the alternative, a plurality of returnmanifold bodies 800 may define respective portions of an integrallyformed return manifold 204.

A return manifold body 800 may be configured to modify a cross-sectionalsurface area of a process gas flow field flowing into the returnmanifold 204 and through the return manifold body 800. A flow fieldflowing into the return manifold body 800 may have an elongatecross-sectional profile, corresponding, for example, to a crossflowplenum 311 defined by a crossflow chamber 310 and/or a downflow plenum309 defined by a downflow chamber 308. A flow field exiting the returnmanifold body 800, such as into one or more process gas evacuation lines208, may have a circular cross-sectional profile, corresponding, forexample, to the one or more process gas evacuation lines 208. A flowfield flowing into the return manifold body 800 may include a lateralflow field with a lateral directional vector 262. The lateral flow fieldand/or the lateral directional vector 262 may correspond to anorientation of a crossflow plenum 311 defined by a crossflow chamber310, Additionally, or in the alternative, the lateral flow field and/orthe lateral directional vector 262 may correspond to an orientation of adownward flow of process gas redirected and/or accelerated laterallyinto the return manifold body 800. A flow field existing the returnmanifold body 800 may include an upward directional vector 266corresponding, for example to an orientation of a process gas evacuationline 208.

A return manifold 204 may include one or more return manifold inlets 802and one or more return manifold outlets 804. The return manifold 204 mayinclude one more return manifold pathways 806 defined at least in partby the return manifold body 800. One or more return manifold pathwaywalls 808 may define at least a portion of one or more return manifoldpathways 806. The one or more return manifold pathway walls 808 may bedisposed within the return manifold body 800, and/or the one or morereturn manifold pathway walls 808 may be integrally formed with thereturn manifold body 800 as a single component. Process gas entering areturn manifold inlet 802 may flow through the one more return manifoldpathways 806 and exit the return manifold 204 at the one or more returnmanifold outlets 804.

The one or more return manifold inlets 802 may be configured to receivea lateral flow of process gas, such as from a crossflow plenum 311defined by a crossflow chamber 310 and/or from an irradiation plenum 121defined by an irradiation chamber 120. Additionally, or in thealternative, the one or more return manifold inlets 802 may beconfigured to receive a flow of process gas, such as a lateral flowand/or a laterally accelerating flow from a downflow plenum 309 definedby a downflow chamber 308 and/or from an irradiation plenum 121 definedby an irradiation chamber 120. The lateral flow of process gas receivedby a return manifold inlet 802 may have an elongate cross-sectionalsurface area. The return manifold body 800 may have a shape thatconforms the cross-sectional surface area of a flow field from an inletcross-sectional surface area, corresponding to one or more returnmanifold inlets 802, to an outlet cross-sectional surface area,corresponding to one or more return manifold outlets 804.

As shown, a return manifold inlet 802 may have an elongatecross-sectional profile, such as a circular cross-sectional profile. Asshown, the elongate cross-sectional surface area of a return manifoldinlet 802 may have a rectangular cross-sectional profile; however, othercross-sectional profiles are also contemplated, including curvilinearcross-sectional profiles, such as an elliptical cross-sectionalprofiles. The one or more return manifold outlets 804 may have anelliptical cross-sectional profile, such as a circular cross-sectionalprofile. However, return manifold outlets 804 with other cross-sectionalprofiles are also contemplated, including return manifold inlets 802with rectangular or polygonal cross-sectional profiles.

A return manifold outlet 804 may discharge a flow of process gassupplied from one or more return manifold inlets 802. Additionally, orin the alternative, a return manifold outlet 804 may discharge a flow ofprocess gas from one or more return manifold pathways 806. The number ofreturn manifold outlets 804 may exceed the number of return manifoldinlets 802 by at least one. A return manifold 204 may include one ormore return manifold inlets 802 and a plurality of return manifoldoutlets 804, such as from one to three return manifold outlets 804 andfrom two to six return manifold inlets 802, such as one, two, or threereturn manifold inlets 802, and two, three, four, five, or six returnmanifold outlets 804. As shown in FIG. 8A, a return manifold 204 mayinclude one return manifold inlet 802 and two return manifold outlets804.

The configuration and arrangement of the return manifold body 800 may bedetermined at least in part to receive a lateral flow field with desiredflow characteristics. The return manifold body 800, the one or morereturn manifold pathways 806, and/or the one or more return manifoldpathway walls 808 may be configured to modify a cross-sectional profileof a flow field received by the return manifold 204. The cross-sectionalprofile of the flow field may be modified with respect to geometryand/or surface area. The cross-sectional profile of the flow field maybe modified from an elongate cross-sectional profile, such as arectangular cross-sectional profile, at the return manifold inlet 802,to an elliptical cross-sectional profile, such as a circularcross-sectional profile, at the one or more return manifold outlets 804.Additionally, or in the alternative, the return manifold body 800, theone or more return manifold pathways 806, and/or the one or more returnmanifold pathway walls 808 may be configured to modify a directionalvector of the flow field. For example, the directional vector of theflow field may be modified from a lateral directional vector 262 at thereturn manifold inlet 802 to an upward directional vector 266 at the oneor more return manifold outlets 804.

The return manifold body 800 may include one more return manifoldpathways 806 that have a curvilinear profile. The curvilinear profile ofthe one more return manifold pathways 806 may facilitate a change in oneor more geometric dimensions of the one more return manifold pathways806 from the one or more return manifold inlets 802 to the one or moreone or more return manifold outlets 804. Additionally, or in thealternative, the curvilinear profile of the one more return manifoldpathways 806 may facilitate a change in the directional vector of theflow field of process gas from the one or more return manifold inlets802 to the one or more one or more return manifold outlets 804. Thereturn manifold body 800 may contract transversely relative to alongitudinal axis 810 of one or more return manifold outlets 804 and/orrelative to a lateral axis 812 of a return manifold inlet 802. Thecurvilinear profile of the one more return manifold pathways 806 mayfacilitate a change in one or more geometric dimensions, and/or a changein the directional vector of the flow field of process gas from thereturn manifold inlet 802 to the one or more one or more return manifoldoutlets 804, without significantly disrupting a boundary layer airwithin the return manifold body 800, such as within the one or morerespective return manifold pathways 806. For example, the curvilinearprofile of the one or more return manifold pathways 806 may avoid formdrag and flow separation, for example, by creating counter-rotatingvortices which draw process gas further into the one or more respectivereturn manifold pathways 806. At least a portion of the curvilinearprofile return manifold body 800 may emulate at least a portion of anNACA air duct.

The return manifold body 800 may include an upward translation region814 and/or a transverse contraction region 816. The upward translationregion 814 may be located downstream from a return manifold inlet 802.The upward translation region 814 includes a region of the returnmanifold body 800 that exhibits an upward translation in the axialorientation of the return manifold body 800, for example, relative tothe lateral axis 812 of a return manifold inlet 802 and/or relative to alongitudinal axis 810 of one or more return manifold outlets 804. Theaxial orientation of the return manifold body 800 may be aligned withthe lateral axis 812, for example, at the return manifold inlet 802. Theaxial orientation of the return manifold body 800 may be aligned withthe longitudinal axis 810, for example, at the one or more returnmanifold outlets 804. The alignment of the axial orientation of thereturn manifold body 800 may transition upwardly within the upwardtranslation region 814, for example, providing increasing alignment withthe longitudinal axis 810 and/or decreasing alignment with the lateralaxis 812. The upward translation region 814 may include a translation ofthe axial orientation of the return manifold body 800 from being alignedwith the lateral axis 812 to being aligned with the longitudinal axis810. However, the return manifold body 800 need not be aligned preciselywith the lateral axis 812 and/or the return manifold body 800 need notbe aligned precisely with the longitudinal axis 810. At least some of aplurality of return manifold pathways 806 may exhibit an upwardtranslation in the respective axial orientation within in the upwardtranslation region 814 as described with reference to the returnmanifold body 800. The rate of upward translation may differ as betweenrespective ones of the plurality of return manifold pathways 806.

The transverse contraction region 816 may be located downstream from anupward translation region 814. Additionally, or in the alternative, thetransverse contraction region 816 may be located upstream from a returnmanifold outlet 804. The transverse contraction region 816 includes aregion of the return manifold body 800 that exhibits a transversecontraction relative to the lateral axis 812 of a return manifold inlet802 and/or relative to a longitudinal axis 810 of one or more returnmanifold outlets 804. At least one of the one or more return manifoldpathways 806 may exhibit a transverse contraction in the transversecontraction region 816 described with reference to the return manifoldbody 800. The rate of transverse contraction may differ as betweenrespective ones of a plurality of return manifold pathways 806. One ormore of a plurality of return manifold pathways 806 need not exhibit atransverse contraction while at least some of the plurality of returnmanifold pathways 806 exhibit a transverse contraction within thetransverse contraction region 816.

At least a portion of the upward translation region 814 may overlap withat least a portion of the transverse contraction region 816.Additionally, or in the alternative, at least a portion of the upwardtranslation region 814 may be separated from at least a portion of thetransverse contraction region 816. For example, a return manifold body800 may include a longitudinal extension region 818 disposed between atleast a portion of the upward translation region 814 and at least aportion of the transverse contraction region 816. The longitudinalextension region 818 represents a region of the return manifold body 800that exhibits a longitudinal extension relative to the longitudinal axis810 of a return manifold outlet 804. At least one of the one or morereturn manifold pathways 806 may exhibit a longitudinal extension in thelongitudinal extension region 818 described with reference to the returnmanifold body 800. The degree of longitudinal extension region 818 maydiffer as between respective ones of the one or more return manifoldpathways 806. At least one of the one or more return manifold pathways806 need not exhibit a longitudinal extension while at least one of theone or more return manifold pathways 806 may exhibit a longitudinalextension within the longitudinal extension region 818.

A return manifold body 800 may include a lateral profiling region 820.The lateral profiling region 820 represents a region of the returnmanifold body 800 that exhibits a lateral change in cross-sectionalprofile, for example, relative to the cross-sectional profile of thereturn manifold inlet 802. For example, the cross-sectional profile ofthe return manifold body 800 may change laterally from a cross-sectionalprofile at the return manifold inlet 802 to a cross-sectional profile atthe one or more return manifold outlets 804. At least some of aplurality of return manifold pathways 806 may exhibit a lateral changein cross-sectional profile in the lateral profiling region 820 describedwith reference to the return manifold body 800. The rate of change inthe lateral cross-sectional profile may differ as between respectiveones of the plurality of return manifold pathways 806. One or more ofthe plurality of return manifold pathways 806 need not exhibit a lateralchange in cross-sectional profile while at least some of the pluralityof return manifold pathways 806 exhibit a lateral change incross-sectional profile within the lateral profiling region 820.

The lateral profiling region 820 may overlap at least a portion of theupward translation region 814 and/or at least a portion of thetransverse contraction region 816. Additionally, or in the alternative,at least a portion of the lateral profiling region 820 may be separatedfrom at least a portion of the upward translation region 814 and/or fromat least a portion of the transverse contraction region 816. The lateralprofiling region 820 may overlap at least a portion of the longitudinalextension region 818. Additionally, or in the alternative, at least aportion of the lateral profiling region 820 may be separated from atleast a portion of the longitudinal extension region 818. Thelongitudinal extension region 818 may be disposed between at least aportion of the lateral profiling region 820 and at least a portion ofthe upward translation region 814. The longitudinal extension region 818may exhibit a longitudinal extension relative to the longitudinal axis810 of a return manifold outlet 804, without a lateral change incross-sectional profile such as may be exhibited in the lateralprofiling region 820. At least one of the one or more return manifoldpathways 806 may exhibit a longitudinal extension in the longitudinalextension region 818, without a lateral change in cross-sectionalprofile such as may be exhibited in the lateral profiling region 820. Atleast one of the one or more plurality of return manifold pathways 806need not exhibit a lateral change in cross-sectional profile, while atleast one of the one or more return manifold pathways 806 may exhibit alateral change in cross-sectional profile within the lateral profilingregion 820.

One or more geometric properties of the one or more return manifoldpathways 806, and/or of the cross-sectional profile of the flow field,may be modified at one or mor regions from the return manifold inlet 802to the one or more return manifold outlets 804. For example, an elongatecross-sectional profile, such as a rectangular cross-sectional profile,at the return manifold inlet 802 may be confirmed to an ellipticalcross-sectional profile, such as a circular cross-sectional profile, atthe one or more return manifold outlets 804. Additionally, or in thealternative, the cross-sectional surface area of the cross-sectionalprofile of the flow field may be modified as between the return manifoldinlet 802 and the one or more return manifold outlets 804. In variousembodiments, the cross-sectional surface area may be increased,decreased, and/or maintained. The cross-sectional surface area of theflow field may remain substantially equivalent as between the returnmanifold inlet 802 and the one or more return manifold outlets 804.Additionally, or in the alternative, the cross-sectional surface areamay be decreased from the return manifold inlet 802 to the one or morereturn manifold outlets 804, for example, in an amount of from about 5%to about 90%, such as from about 10% to about 80%, or such as from about25% to about 75%. The decreasing cross-sectional surface area mayprovide a pressure increase and/or an increase in velocity of the flowfield, which may result in good receipt and evacuation of the processgas. The cross-sectional surface area of the return manifold inlet 802and the cross-sectional surface area of the one or more return manifoldoutlets 804 may be within about 25% of one another, such as within about10% of one another, such as within about 5% of one another, or such aswithin about 1% of one another. Additionally, or in the alternative, thecross-sectional surface area of the return manifold inlet 802 and thecross-sectional surface area of the one or more return manifold outlets804 may differ from one another by up to 125%, such as up to 100%, suchas up to 50%, such as up to 25%. Such a pressure increase may bedetermined from pressure measurements obtained with one or more pressuresensors configured to determine an upstream pressure and a downstreampressure, and or a pressure differential. By way of example, suchpressure or pressure differential may be determined by a differentialpressure sensor

The one or more return manifold inlets 802 may have a width and a heightthat are proportioned such that the width exceeds the height, forexample, by a factor of from about 10:1 to 100:1, such as from about10:1 to about 50:1, or such as from about 10:1 to about 20:1. A width ofthe lateral flow field of process gas discharged from the one or morereturn manifold outlets 804 may exceed a height of the lateral flowfield. For example, a ratio of the width of the lateral flow field tothe height of the lateral flow field may be from about 10:1 to 100:1,such as from about 10:1 to about 50:1, or such as from about 10:1 toabout 20:1.

A cross-sectional surface area of one or more return manifold inlets 802may correspond to a cross-sectional surface area of one or morecrossflow manifold outlets 504 and/or to a cross-sectional surface areaof a plurality of downflow manifold pathways 418. For example, across-sectional surface area of one or more return manifold inlets 802may be configured to receive a volume of process gas corresponding to avolume of process gas from one or more crossflow manifold outlets 504and/or from one or more downflow manifold pathways 418. Across-sectional surface area of one or more return manifold inlets 802may be substantially equivalent to the cross-sectional surface area ofone or more crossflow manifold outlets 504 and/or one or more downflowmanifold pathways 418 from which the one or more return manifold inlets802 are intended to receive process gas. For example, the across-sectional surface area of one or more return manifold inlets 802may be within about 25% of the cross-sectional surface area of one ormore crossflow manifold outlets 504 and/or one or more downflow manifoldpathways 418 from which the one or more return manifold inlets 802 areintended to receive process gas, such as within about 15%, such aswithin about 10%, or such as within about 5% of the cross-sectionalsurface area of one or more crossflow manifold outlets 504 and/or one ormore downflow manifold pathways 418 from which the one or more returnmanifold inlets 802 are intended to receive process gas. Additionally,or in the alternative, the a cross-sectional surface area of one or morereturn manifold inlets 802 may be slightly larger, such as up to about25% larger, than the cross-sectional surface area of one or morecrossflow manifold outlets 504 and/or one or more downflow manifoldpathways 418 from which the one or more return manifold inlets 802 areintended to receive process gas, such as up to about 15% larger, such asup to about 10% larger, or such as up to about 5% larger than thecross-sectional surface area of one or more crossflow manifold outlets504 and/or one or more downflow manifold pathways 418 from which the oneor more return manifold inlets 802 are intended to receive process gas.

In addition, or in the alternative, to changing a cross-sectionalprofile of a flow field, the return manifold body 800 may be configuredto change a directional vector of the flow field. The return manifoldbody 800 may include one or more return manifold inlets 802 respectivelyfluidly communicating with an irradiation plenum 121 defined by anirradiation chamber 120, a crossflow plenum 311 defined by a crossflowchamber 310, and/or a downflow plenum 309 defined by a downflow chamber308. The return manifold body 800 may be configured to change adirection vector of the flow field at the return manifold inlet 802 to adirectional vector at the one or more return manifold outlets 804. Thereturn manifold body 800 may modify a lateral directional vector 262 atthe return manifold inlet 802 to an upward directional vector 266 at theone or more return manifold outlets 804. The return manifold body 800may provide an upward accelerating directional vector 268. Themodification to the directional vector from the return manifold inlet802 to the one or more return manifold outlets 804 may be about 90degrees, such as from about 80 degrees to about 100 degrees, such asfrom about 85 to about 95 degrees. Additionally, or in the alternative,the directional vector of a flow field may be modified from the returnmanifold inlet 802 to the one or more return manifold outlets 804 in anamount of from about 10 degrees to about 100 degrees, such as from about30 degrees to about 90 degrees, such as from about 60 degrees to about90 degrees, or from about 10 degrees to about 45 degrees.

A lateral axis 812 of a return manifold inlet 802 may be orientedparallel to the build plane 225, or substantially parallel to the buildplane 225, such as within about 10 degrees of parallel to the buildplane 225, such as within about 5 degrees of parallel to the build plane225, or within about 1 degree of parallel to the build plane 225.Additionally, or in the alternative, a lateral axis 812 of a returnmanifold inlet 802 may be oriented oblique to the build plane 225, suchas from about 5 degrees to about 85 degrees, such as from about 30degrees to about 85, such as from about 60 degrees to about 80 degrees,or such as from about 10 degrees to about 45 degrees relative to thebuild plane 225. Additionally, or in the alternative, a lateral axis 812of a return manifold inlet 802 may be oriented perpendicular to thebuild plane 225, or substantially perpendicular to the build plane 225,such as at about 90 degrees relative to the build plane 225, such asfrom about 80 to 100 degrees relative to the build plane 225, or such asfrom about 85 to 95 degrees relative to the build plane.

In addition, or in the alternative, to an orientation of the lateralaxis 812 of a return manifold inlet 802 relative to the build plane 225,the lateral axis 812 of a return manifold inlet 802 may be oriented maybe oriented perpendicular, or substantially perpendicular to thelongitudinal axis 424 of the downflow manifold body 400, such as such aswithin about 10 degrees of perpendicular to the longitudinal axis 424 ofthe downflow manifold body 400, such as within about 5 degrees ofperpendicular to the longitudinal axis 424 of the downflow manifold body400, or such as within about 1 degree of perpendicular the longitudinalaxis 424 of the downflow manifold body 400. Additionally, or in thealternative, the lateral axis 812 of a return manifold inlet 802 may beoriented oblique to the longitudinal axis 424 of the downflow manifoldbody 400, such as from about 5 degrees to about 85 degrees relative tothe longitudinal axis 424 of the downflow manifold body 400, such asfrom about 30 degrees to about 85, such as from about 60 degrees toabout 80 degrees, such as from about 10 degrees to about 45 degreesrelative to the longitudinal axis 424 of the downflow manifold body 400.

Additionally, or in the alternative, the lateral axis 812 of a returnmanifold inlet 802 may be oriented perpendicular or substantiallyperpendicular to the longitudinal axis 316 of the irradiation chamber120 and/or crossflow chamber 310, such as within about 10 degrees ofperpendicular to the longitudinal axis 316 of the irradiation chamber120 and/or crossflow chamber 310, such as within about 5 degrees ofperpendicular to the longitudinal axis 316 of the irradiation chamber120 and/or crossflow chamber 310, or within about 1 degree ofperpendicular to the longitudinal axis 316 of the irradiation chamber120 and/or crossflow chamber 310. Additionally, or in the alternative,the lateral axis 812 of a return manifold inlet 802 may be orientedoblique to the longitudinal axis 316 of the irradiation chamber 120and/or crossflow chamber 310, such as from about 5 degrees to about 85degrees relative to the longitudinal axis 316 of the irradiation chamber120 and/or crossflow chamber 310, such as from about 30 degrees to about85, such as from about 60 degrees to about 80 degrees, such as fromabout 10 degrees to about 45 degrees relative to the longitudinal axis316 of the irradiation chamber 120 and/or crossflow chamber 310.Additionally, or in the alternative, the lateral axis 812 of a returnmanifold inlet 802 may be oriented parallel or substantially parallel tothe longitudinal axis 316 of the irradiation chamber 120 and/orcrossflow chamber 310, such as within about 10 degrees of parallel tothe longitudinal axis 316 of the irradiation chamber 120 and/orcrossflow chamber 310, such as within about 5 degrees of parallel to thelongitudinal axis 316 of the irradiation chamber 120 and/or crossflowchamber 310, or within about 1 degree of parallel to the longitudinalaxis 316 of the irradiation chamber 120 and/or crossflow chamber 310.

A longitudinal axis 810 of the one or more return manifold outlets 804may be oriented perpendicular to the build plane 225, or substantiallyperpendicular to the build plane 225, such as at about 90 degreesrelative to the build plane 225, such as within about 10 degrees ofperpendicular to the build plane 225, such as within about 5 degrees ofperpendicular to the build plane 225, or within about 1 degree ofperpendicular to the build plane 225. The one or more return manifoldoutlets 804 may discharge an upward flow field with an upwarddirectional vector 266 oriented perpendicular to the build plane 225, orsubstantially perpendicular to the build plane 225, such as at about 90degrees relative to the build plane 225, such as within about 10 degreesof perpendicular to the build plane 225, such as within about 5 degreesof perpendicular to the build plane 225, or within about 1 degree ofperpendicular to the build plane 225. The upward directional vector 266may be oriented oblique relative to the build plane 225, such as fromabout 5 degrees to about 85 degrees relative to the build plane 225,such as from about 30 degree to about 60 degrees relative to the buildplane 225, or such as from about 45 degrees to about 85 degrees relativeto the build plane 225.

Referring now to FIG. 8B, a return manifold 204 may include one or morenarrowing regions 821 representing a reduction in cross-sectional heightof a return manifold inlet 802 and/or within a return manifold pathway806. The one or more narrowing regions 821 may extend across all or aportion of a width of the return manifold inlet 802 and/or returnmanifold pathway 806. The one or more narrowing regions 821 may belocated upstream from an upward translation region 814 of the returnmanifold body 800. The reduction in cross-sectional height may beprovided with respect to a portion of the return manifold body 800disposed above and/or below the return manifold inlet 802 and/or returnmanifold pathway 806. The one or more narrowing regions 821 may providea venturi effect that accelerates process gas into and/or through thereturn manifold inlet 802 and/or the return manifold pathway 806.

As shown in FIG. 8B, in addition, or in the alternative to, one or morenarrowing regions 821, a return manifold 204 may include one or more ribelements 822 protruding into the return manifold inlet 802 and/or intothe return manifold pathway 806. The narrowing region 821 and/or the oneor more rib elements 822 may be disposed about a return manifold inlet802 and/or within a return manifold pathway 806. For example, as shownin FIG. 8B, a narrowing region 821 and/or a rib element 822 may bedisposed within a return manifold pathway 806 and downstream from aninlet edge 824 of a return manifold inlet 802. Additionally, or in thealternative, as shown, a narrowing region 821 and/or a rib element 822may be disposed within the return manifold pathway 806 and upstream fromthe upward translation region 814 of the return manifold body 800. Theone or more narrowing regions 821 and/or the one or more rib elements822 may be located at any position about the return manifold inlet 802and/or within a return manifold pathway 806. As shown, a narrowingregion and/or a rib element 822 may be disposed across a bottom portionof a return manifold pathway 806. Additionally, or in the alternative,one or more narrowing regions 821 and/or one or more rib elements 822may be disposed across a top portion and/or a side portion of a returnmanifold pathway 806. A narrowing region 821 and/or a rib element 822may extend across all or part of a bottom, top, or side portion of areturn manifold pathway 806. The one or more narrowing regions 821and/or the one or more rib elements 822 may be integrally formed as partof a return manifold body 800. Additionally, or in the alternative, oneor more narrowing regions 821 and/or one or more rib elements 822 may befixedly coupled to a return manifold body 800 as a separate component.

The one or more narrowing regions 821 and/or the one or more ribelements 822 may provide a pressure reduction within the return manifoldinlet 802 and/or within the one or more return manifold pathways 806that accelerates process gas flowing into the return manifold inlet 802and/or through the one or more return manifold pathways 806. Such apressure reduction may be determined from pressure measurements obtainedwith one or more pressure sensors configured to determine an upstreampressure and a downstream pressure, and or a pressure differential, withrespect to the one or more narrowing regions 821 and/or the one or morerib elements 822. By way of example, such pressure or pressuredifferential may be determined by a differential pressure sensor. Theone or more narrowing regions 821 and/or the one or more rib elements822 may increase the efficiency of process gas recapture by the returnmanifold 204, for example, by drawing process gas into the returnmanifold inlet 802. Additionally, or in the alternative, the one or morenarrowing regions 821 and/or the one or more rib elements 822 may reduceor prevent process gas losses. For example, a narrowing region 821and/or a rib element 822 disposed across a bottom portion of a returnmanifold pathway may prevent process gas from flowing beneath the returnmanifold inlet 802 and/or the return manifold body 800.

As shown in FIG. 8B, a return manifold body 800 may include one or morerecapture pathways 826 configured to receive process gas that flows pastthe return manifold inlet 802 into the one or more return manifoldpathways 806. For example, the one or more recapture pathways 826 mayreceive process gas that flows beneath the return manifold inlet 802.The one or more recapture pathways 826 may be in the form of an elongateslit; however, other pathway configurations are also contemplated, suchas an array of apertures, an array of perforations, a lattice, agrating, or the like. The one or more recapture pathways 826 may bedisposed across at least a portion of a return manifold pathway 806,such as across a bottom portion, a top portion, and/or a side portion ofa return manifold pathway 806. For example, as shown, a recapturepathway 826 may be disposed transversely across a bottom portion of areturn manifold pathway 806. As shown, the one or more recapturepathways 826 may fluidly communicate with a return manifold pathway 806downstream from an inlet edge 824 of a return manifold inlet 802.Additionally, or in the alternative, One or more recapture pathways 826may fluidly communicate with a return manifold pathway 806 upstream froma narrowing region and/or a rib element 822, such as upstream from afoil edge 828 of a rib element 822. Additionally, or in the alternative,as shown, one or more recapture pathways 826 may be disposed within areturn manifold pathway 806 and upstream from an upward translationregion 814 of a return manifold body 800.

The one or more recapture pathways 826 may recapture process gas thatflows past the return manifold inlet 802. For example, as shown in FIG.8B, process gas flowing beneath the return manifold inlet 802 and/or thereturn manifold body 800 may be recaptured and drawn into the returnmanifold pathway 806 by the one or more recapture pathways 826. When theone or more recapture pathways 826 are disposed upstream from one ormore narrowing regions 821 and/or one or more rib elements 822, apressure reduction provided by the one or more narrowing regions 821and/or the one or more rib elements 822 may accelerate process gasthrough the one or more recapture pathways 826 and into the returnmanifold pathway 806. For example, a recapture pathway 826 followed by anarrowing region 821 and/or a rib element 822 disposed across a bottomportion of a return manifold pathway 806 may work with one another torecapture process gas that may flow beneath the return manifold inlet802.

Now turning to FIGS. 9A-9D, exemplary crossflow walls 314 of a crossflowchamber 310 will be further described. As shown in FIGS. 9A-9D, acrossflow wall 314 may include one or more flanges 900 with attachmentpoints 901 configured to couple a crossflow wall 314 to a crossflowmanifold 222, to a return manifold 204, and/or to a downflow wall 312.Additionally, or in the alternative, a crossflow wall 314 may beintegrally formed with a crossflow manifold 222, a return manifold 204,and/or to a downflow wall 312, as a single component.

As shown, a crossflow wall 314 may include a crossflow manifold flange902 with one or more attachment points 901 configured to couple thecrossflow wall 314 to a crossflow manifold 222. Additionally, or in thealternative, a crossflow wall 314 may include a return manifold flange904 with one or more attachment points 901 configured to couple thecrossflow wall 314 to a return manifold 204. Further additionally, or inthe alternative, a crossflow wall 314 may include a downflow wall flange906 with one or more attachment points 901 configured to couple thecrossflow wall 314 to a downflow wall 312.

A crossflow wall 314 may include one or more bevels 908 disposed betweena face 910 of the crossflow wall 314 and respective ones of the one ormore flanges 900. The one or more bevels 908 may slope away from therespective flanges 900, which may help prevent contaminants fromaccumulating around the respective flanges 900 and/or reduceaccumulation of contaminants from around the respective flanges 900,such as where the flanges respectively attach to a crossflow manifold222, to a return manifold 204, and/or to a downflow wall 312. Therespective attachment points 901 of the crossflow manifold 222, thereturn manifold 204, and/or the downflow wall 312 may have acorresponding bevel (not shown) configured to mate with the respectivebevel 908 on the crossflow wall 314.

As shown, a crossflow wall 314 may include a crossflow manifold bevel912 corresponding to a crossflow manifold flange 902. Additionally, orin the alternative, a crossflow wall 314 may include a return manifoldbevel 914 corresponding to a return manifold flange 904. Furtheradditionally, or in the alternative, a crossflow wall 314 may include adownflow wall bevel 916 corresponding to a downflow wall flange 906.

As shown in FIGS. 9D and 9E, a crossflow wall 314 may include acrossflow ledge 918 disposed along a bottom portion of the crossflowwall 314, such as a bottom inward lateral edge of the crossflow wall314. The crossflow ledge 918 may protrude transversely from thecrossflow wall 314, such as inward towards a lateral axis 318 of acrossflow chamber 310 (e.g., FIGS. 3A-3D). The crossflow ledge 918 mayprevent process gas from escaping under the bottom portion of thecrossflow wall 314. For example, the crossflow ledge 918 may generateturbulence that lifts process gas flowing adjacent to the crossflowledge 918 and redirects such process gas into the bulk flow of the flowfield flowing through the crossflow plenum 311 defined by the crossflowchamber 310.

As shown in FIGS. 9E, a crossflow wall 314 may include an outward ledge920 disposed along a bottom portion of the crossflow wall 314, such as abottom outward lateral edge of the crossflow wall 314. A crossflow wallmay include an outward ledge 920 in addition, or in the alternative to,a crossflow ledge 918. The outward ledge 920 may protrude transverselyfrom the crossflow wall 314, such as exterior from the crossflow chamber310 (e.g., FIGS. 3A-3D). The outward ledge 920 may prevent process gasfrom escaping under the bottom portion of the crossflow wall 314. Forexample, the outward ledge 920 may present an increased distance forprocess gas to travel before escaping from under the bottom portion ofthe crossflow wall 314. The outward ledge 920 may function independentlyfrom, or in coordination with, the crossflow ledge 918. For example,turbulence generated by the crossflow ledge 918 may draw process gasfrom beneath the outward ledge and back into the crossflow chamber 310.

Now turning to FIGS. 10A-10F, exemplary flow fields will be described.As shown in FIGS. 10A and 10B, process gas flowing through one or moreprocess gas supply line 206 to a crossflow manifold 222 may have adownward directional vector 260. Process gas flowing from a crossflowmanifold 222 into a crossflow plenum 311 may have a laterallyaccelerating directional vector 264, for example, as the directionalflow of the process gas changes from a downward direction to a lateraldirection. Process gas flowing through a crossflow plenum 311 may have alateral directional vector 262. Process gas may flow from the crossflowplenum 311 into a return manifold 204 with a lateral directional vector.Process gas flowing through the return manifold 204 may have an upwardaccelerating directional vector 268. Process gas may exit the returnmanifold 204, flowing into one or more process gas evacuation lines 208with an upward directional vector. Additionally, or in the alternative,process gas flowing into an irradiation plenum 121 and/or a downflowplenum 309 may have a downward directional vector 260. Process gasflowing from the irradiation plenum into the crossflow plenum 311 and/orinto the return manifold 204 may have a laterally acceleratingdirectional vector 264.

A flow field of process gas may have different properties with respectto different regions of an irradiation plenum 121, a crossflow plenum311, and/or a downflow plenum 309. Additionally, or in the alternative,a plurality of flow fields with one or more respectively differentproperties may be determinable within the irradiation plenum 121, thecrossflow plenum 311, and/or the downflow plenum 309. As shown in FIG.10A, a flow of process gas through a crossflow flow plenum 311 mayinclude a crossflow flow field 350 with a relatively high velocity, forexample, in comparison to one or more other flow fields within theirradiation plenum 121 and/or the downflow plenum 309. The crossflowflow field 350 may occupy all or a portion of the crossflow plenum 311.A crossflow flow field 350 may represent the highest velocity in theirradiation plenum 121.

As shown in FIGS. 10A and 10B, a flow of process gas through a downflowplenum 309 may include a primary downflow flow field 352. The primarydownflow flow field 352 may include a region of the downward flow ofprocess gas that has a relatively moderate velocity, for example,relative to the crossflow flow field 350. The primary downflow flowfield 352 may occupy an annular or semiannular region extendinglongitudinally below at least a portion of the downflow manifold 210.The process gas in the primary downflow flow field 352 may be suppliedfrom a downflow manifold 210, such as from a plurality of downflowmanifold apertures 422 disposed about one or more walls of the downflowmanifold 210. A flow of process gas through a downflow plenum 309 mayinclude a quiescent downflow flow field 354. The quiescent downflow flowfield 354 may represent a region of the downflow plenum 309 thatexhibits a relatively quiescent flow of process gas, such as relativelylatent, mild, and/or gentle flow of process gas. The quiescent downflowflow field 354 may be disposed below one or more optics windows 234 thatseparate one or more optical elements 233 of an irradiation device 216from the irradiation plenum 121. The quiescent downflow flow field 354may be at least partially surrounded by the primary downflow flow field352. For example, at least a portion of the primary downflow flow field352 may circumferentially surround at least a portion of the quiescentdownflow flow field 354. The quiescent downflow flow field 354 mayexhibit a crossflow, for example, with a radially outward directionalvector and/or a downwardly accelerating directional vector 360. Such acrossflow may be located in a region of the downflow plenum 309 adjacentto the one or more optics windows 234.

A flow of process gas through a downflow plenum 309 may include anintermediate downflow flow field 356. The intermediate downflow flowfield 356 may be disposed between a primary downflow flow field 352 anda quiescent downflow flow field 354. The intermediate downflow flowfield 356 may represent a transition region of the downflow plenum 309,such as a transition from the primary downflow flow field 352 to thequiescent downflow flow field 354. The intermediate downflow flow field356 may occupy an annular or semiannular region of the downflow plenum309, such as an annular or semiannular region extending longitudinallybelow at least a portion of the downflow manifold 210 and/or at least aportion of the one or more optics windows 234 that separate one or moreoptical elements 233 of an irradiation device 216 from the irradiationplenum 121.

The intermediate downflow flow field 356 may be at least partiallysurrounded by the primary downflow flow field 352. For example, at leasta portion of the primary downflow flow field 352 may circumferentiallysurround at least a portion of the intermediate downflow flow field 356.Additionally, or in the alternative, the intermediate downflow flowfield 356 may at least partially surround the quiescent downflow flowfield 354. For example, at least a portion of the intermediate downflowflow field 356 may circumferentially surround at least a portion of thequiescent downflow flow field 354. At least a portion of theintermediate downflow flow field 356 may occupy a radially inward regionof the downflow plenum 309, such as a radially inward region extendinglongitudinally below at least a portion of the quiescent downflow flowfield 354.

Still referring to FIGS. 10A and 10B, a flow of process gas through adownflow plenum 309 may include a lateral acceleration flow field 358.The lateral acceleration flow field 358 may include a portion of thedownflow plenum 309 in which process gas laterally accelerates, forexample, as a result of acceleration and entrainment by the crossflowflow field 350 and/or suction from the return manifold 204. The lateralacceleration flow field 358 may represent a transition region of thedownflow plenum 309, such as a transition from the primary downflow flowfield 352 to the crossflow flow field 350. At least a portion of thelateral acceleration flow field 358 may be disposed between a primarydownflow flow field 352 and a crossflow flow field 350. Additionally, orin the alternative, at least a portion of the lateral acceleration flowfield 358 may be biased laterally towards a return manifold inlet 802and/or relative to the longitudinal axis 316 of the irradiation chamber120. The lateral acceleration flow field 358 may occupy a proximalregion of the downflow plenum 309 relative to the build plane 225, suchas a proximal region extending longitudinally below at least a portionof the downflow manifold 210 and/or at least a portion of the one ormore optics windows 234 that separate one or more optical elements 233of an irradiation device 216 from the irradiation plenum 121.

A flow of process gas through a downflow plenum 309 may include anintermediate lateral acceleration flow field 362. The intermediatelateral acceleration flow field 362 may include a portion of thedownflow plenum 309 in which process gas laterally accelerates in arelatively intermediate rate, for example, in comparison to the lateralacceleration flow field 358, such as from entrainment by the crossflowflow field 350 and/or suction from the return manifold 204. Theintermediate lateral acceleration flow field 362 may represent atransition region of the downflow plenum 309, such as a transition fromthe intermediate downflow flow field 356 to the crossflow flow field350. At least a portion of the intermediate lateral acceleration flowfield 362 may be disposed between an intermediate downflow flow field356 and a crossflow flow field 350. Additionally, or in the alternative,at least a portion of the intermediate lateral acceleration flow field362 may be biased centrally relative to the longitudinal axis 316 of theirradiation chamber 120 and/or laterally towards a crossflow manifoldoutlet 504. The intermediate lateral acceleration flow field 362 mayoccupy a proximal region of the downflow plenum 309 relative to thebuild plane 225, such as a proximal region extending longitudinallybelow at least a portion of the intermediate downflow flow field 356,and/or below at least a portion of the downflow manifold 210 and/or atleast a portion of the one or more optics windows 234. At least aportion of the lateral acceleration flow field 358 may be disposedlaterally adjacent to at least a portion of the intermediate lateralacceleration flow field 362. For example, the lateral acceleration flowfield 358 may be disposed laterally outward relative to the longitudinalaxis 316 of the irradiation chamber 120, and/or the intermediate lateralacceleration flow field 362 may be disposed laterally inward relative tothe longitudinal axis 316 of the irradiation chamber 120.

The bulk flow rate of the process gas in the downflow plenum 309 may beselected to suitably capture contaminants that may propagate out of thecrossflow plenum 311. The regional velocity of the process gas in thedownflow plenum 309 may differ as between different flow field withinthe downflow plenum 309. By way of example, an exemplary downflowvelocity curve 364 represents a differing velocity as between respectiveflow fields is shown in FIGS. 10A and 10B. Relatively higher velocitymay be exhibited in the primary downflow flow field 352, for example, incomparison to relatively lower velocity in the quiescent downflow flowfield 354. Additionally, or in the alternative, relatively intermediatevelocity may be exhibited in the intermediate downflow flow field 356.It will be appreciated that the downflow velocity curve 364 shown inFIGS. 10A and 10B is provided by way of example only, and not to belimiting. It will be appreciated that other velocity curves arecontemplated and are within the scope of the present disclosure, andthat such other velocity curves may be realized by various embodimentsand/or modifications of the features of the presently disclosedinertization system 200.

Referring now to FIG. 10C, an exemplary crossflow plenum 311 is shown,taken from cross-section C-C shown in FIG. 10A. The crossflow plenum 311may exhibit a crossflow flow field 350. The process gas in the crossflowflow field 350may be supplied from a crossflow manifold 222, such asfrom a crossflow manifold outlet 504. A lateral velocity of the processgas in the crossflow flow field 350 flowing through the crossflow plenum311 may exceed a downward velocity of the process gas in the irradiationplenum 121 and/or the downflow plenum 309. For example, the velocity ofthe process gas in the crossflow flow field 350 may be relatively higherthan the velocity of the process gas in the primary downflow flow field352, in the intermediate downflow flow field 356, and/or in thequiescent downflow flow field 354.

The bulk flow rate of the process gas in the crossflow plenum 311 may beselected to suitably remove and/or evacuate contaminants from theirradiation plenum 121, including the crossflow plenum 311 and/or thedownflow plenum 309. The velocity of process gas in the crossflow plenum311 may be selected to rapidly remove and/or evacuate contaminantswithout disturbing powder material 114 in the powder bed 227. Theregional velocity of the process gas in the crossflow plenum 311 may berelatively uniform across the crossflow plenum 311. By way of example,an exemplary crossflow velocity curve 366 represents a relativelyuniform velocity across the crossflow flow field 350. It will beappreciated that the crossflow velocity curve 366 shown in FIG. 10C isprovided by way of example only, and not to be limiting. It will beappreciated that other velocity curves are contemplated and are withinthe scope of the present disclosure, and that such other velocity curvesmay be realized by various embodiments and/or modifications of thefeatures of the presently disclosed inertization system 200.

Referring now to FIGS. 10D-10F, exemplary irradiation chambers 120 andirradiation plenums 121, such as crossflow chambers 310 and crossflowplenums 311, and/or downflow chambers 308 and downflow plenums 309, willbe further described. An irradiation chamber 120 may define anirradiation plenum 121 that includes an irradiation zone 370.Additionally, or in the alternative, a downflow chamber 308 may define adownflow plenum 309 that includes an irradiation zone 370, and/or acrossflow chamber may define a crossflow plenum 311 that includes anirradiation zone 370. The irradiation zone 370 may represent a portionof an irradiation plenum 121, a downflow plenum 309, and/or a crossflowplenum 311, utilized by an energy beam 214 during additivemanufacturing. An irradiation zone 370 may include one or moredimensions that correspond to one or more dimensions of a scan field 212of one or more energy beams 214. For example, an irradiation zone 370and a scan field 212 may have the same cross-sectional surface area atone or more locations along a longitudinal axis 316 of an irradiationchamber 120. Additionally, or in the alternative, an irradiation zone370 may have a cross-sectional surface area that is smaller than thescan field 212 of one or more energy beams 214, for example, at one ormore locations along a longitudinal axis 316 of an irradiation chamber120.

The irradiation zone 370 may occupy all or a portion of a crossflowplenum 311. A crossflow plenum 311 may include an ancillary zone 372.The ancillary zone 372 may include a portion of the crossflow plenum 311that is not utilized by the one or more energy beams 214 during additivemanufacturing. The ancillary zone 372 may represent a portion of anirradiation plenum 121, a downflow plenum 309, and/or a crossflow plenum311, that may remain unused by an energy beam 214 during additivemanufacturing. An ancillary zone 372 may represent a region outside thescan field of the one or more energy beams 214. For example, theancillary zone 372 may surround at least a portion of the irradiationzone 370.

As shown in FIG. 10D-10F, an irradiation chamber 120 may define anirradiation plenum 121 that includes an ancillary zone 372circumferentially surrounding an irradiation zone 370. For example, anirradiation chamber 120 may have a rectangular cross-sectional profile.Additionally, or in the alternative, a crossflow chamber 310 may definea crossflow plenum 311 with a rectangular cross-sectional profile,and/or downflow chamber 308 may define a downflow plenum 309 with arectangular cross-sectional profile. As shown in FIG. 10D, a lateralflow field within the irradiation zone 370 and/or the ancillary zone 372may have a lateral directional vector 262.

As shown in FIG. 10D, a bulk flow 374 of the lateral flow field may besubstantially perpendicular to a lateral axis 318 of the irradiationchamber 120, of the crossflow chamber 310, and/or of the downflowchamber 308. Additionally, or in the alternative, as shown in FIGS. 10Eand 10F, a bulk flow 374 of the lateral flow field may converge towardsthe lateral axis 318 of the irradiation chamber 120, of the crossflowchamber 310, and/or of the downflow chamber 308. A converging bulk flow374 may be realized by a configuration and arrangement of a crossflowmanifold 222, such as a configuration and arrangement of a crossflowmanifold outlet 504. A crossflow manifold outlet 504 may be configuredto provide a converging bulk flow 374 with a lateral directional vector262 that converges towards the lateral axis 318. For example, acrossflow manifold outlet 504 may include one or more crossflow manifoldpathway walls 508 oriented relative to a normal line perpendicular to atangent of a curvilinear crossflow plane 378. Additionally, or in thealternative, a crossflow manifold outlet 504 may include an outlet flowconditioner 700 configured to provide a converging bulk flow 374. Anoutlet flow conditioner 700 may include a plurality of outlet flowconditioning channels 704 oriented relative to a normal lineperpendicular to a tangent of a curvilinear crossflow plane 378.

The convergence of the bulk flow 374 towards the lateral axis 318 mayorient the flow of process gas with respect to the irradiation zone 370,for example, in favor of the ancillary zone 372. For example, as shownin FIG. 10E, by converging the bulk flow 374 towards the lateral axis318, a portion of the ancillary zone 372may be untraversed by the bulkflow 374. Additionally, or in the alternative, a boundary layer 376 ofthe bulk flow 374 may cut across the ancillary zone 372. A convergingbulk flow 374 may help a return manifold 204 recapture process gas. Forexample, converging bulk flow 374 may direct process gas into the returnmanifold inlet 802. Additionally, or in the alternative, a convergingbulk flow 374 may reduce or minimize eddy currents along the boundarylayer 376 of the bulk flow 374, and/or a converging bulk flow 374 mayreduce disruption of the boundary layer 376, such as by interaction fromeddy currents and/or by interactions with the crossflow walls 314.

An irradiation chamber 120, a downflow chamber 308, and/or a crossflowchamber 310, may include one or more crossflow walls 314 that aresubstantially aligned with a boundary layer 376 of a converging bulkflow 374 of process gas. For example, as shown in FIG. 10F, anirradiation chamber 120, a downflow chamber 308, and/or a crossflowchamber 310 may have a trapezoidal cross-sectional profile.Additionally, or in the alternative, one or more crossflow walls 314 maybe oriented convergingly towards a lateral axis 318. With the one ormore crossflow walls 314 oriented convergingly towards the lateral axis318, the return manifold may exhibit improved recapture of process gas.For example, the converging crossflow walls 314 may direct process gasinto the return manifold inlet 802. Additionally, or in the alternative,the converging crossflow walls 314 may reduce or minimize eddy currentsalong the boundary layer 376 of the bulk flow 374, and/or the convergingcrossflow walls 314 may reduce disruption of the boundary layer 376,such as by interaction from eddy currents and/or by interactions betweenthe bulk flow 374 and the crossflow walls 314.

As depicted, for example, in FIG. 10F, a return manifold 204 may beconfigured to receive a converging bulk flow 374. For example, a returnmanifold inlet 802 may be configured to receive a converging bulk flow374. A return manifold inlet 802 may include one or more return manifoldpathway walls 808 oriented relative to a normal line perpendicular to atangent of a curvilinear evacuation plane 380. The normal lineperpendicular to the tangent of the curvilinear evacuation plane 380 maycoincide with a normal line perpendicular to a tangent of a curvilinearcrossflow plane 378 of a crossflow manifold outlet 504 and/or of anoutlet flow conditioner 700.

Now turning to FIG. 11, an exemplary control system for an additivemanufacturing machine 102 or additive manufacturing system 100 will bedescribed. A control system 104 may be configured to perform one or morecontrol operations. A control system 104 may be configured to output oneor more control commands associated with an additive manufacturingmachine 102. The control commands may be configured to control one ormore controllable components of an additive manufacturing machine 102.

As shown in FIG. 11 an exemplary control system 104 includes acontroller 1100. The controller may include one or more control modules1102 configured to cause the controller 1100 to perform one or morecontrol operations. The one or more control modules 1102 may includecontrol logic executable to determine one or more operating parametersfor an additive manufacturing machine 102, such as setpoints for one ormore build units 110 and/or setpoints for one or more inertizationsystems 200, for example, for performing operations in accordance withthe present disclosure. Additionally, or in the alternative, the one ormore control modules 1102 may include control logic executable toprovide control commands configured to control one or more controllablecomponents associated with an additive manufacturing machine 102, suchas controllable components associated with one or more build units 110and/or one or more inertization systems 200. For example, a controlmodule 1102 may be configured to provide one or more control commandsbased at least in part on one or more setpoints for performingoperations in accordance the present disclosure.

The controller 1100 may be communicatively coupled with an additivemanufacturing machine 102. The controller 1100 may be communicativelycoupled with one or more components of an additive manufacturing machine102, such as one or more components of an energy beam system 118, and/ora monitoring system 254. The controller 1100 may also be communicativelycoupled with a management system 106 and/or a user interface 108.

The controller 1100 may include one or more computing devices 1104,which may be located locally or remotely relative to the additivemanufacturing machine 102 and/or the monitoring system 254. The one ormore computing devices 1104 may include one or more processors 1106 andone or more memory devices 1108. The one or more processors 1106 mayinclude any suitable processing device, such as a microprocessor,microcontroller, integrated circuit, logic device, and/or other suitableprocessing device. The one or more memory devices 1108 may include oneor more computer-readable media, including but not limited tonon-transitory computer-readable media, RAM, ROM, hard drives, flashdrives, and/or other memory devices 1108.

As used herein, the terms “processor” and “computer” and related terms,such as “processing device” and “computing device”, are not limited tojust those integrated circuits referred to in the art as a computer, butbroadly refers to a microcontroller, a microcomputer, a programmablelogic controller (PLC), an application specific integrated circuit, andother programmable circuits, and these terms are used interchangeablyherein. A memory device 1108 may include, but is not limited to, anon-transitory computer-readable medium, such as a random access memory(RAM), and computer-readable nonvolatile media, such as hard drives,flash memory, and other memory devices. Alternatively, a floppy disk, acompact disc-read only memory (CD-ROM), a magneto-optical disk (MOD),and/or a digital versatile disc (DVD) may also be used.

As used herein, the term “non-transitory computer-readable medium” isintended to be representative of any tangible computer-based deviceimplemented in any method or technology for short-term and long-termstorage of information, such as, computer-readable instructions, datastructures, program modules and sub-modules, or other data in anydevice. The methods described herein may be encoded as executableinstructions embodied in a tangible, non-transitory, computer readablemedia, including, without limitation, a storage device and/or a memorydevice. Such instructions, when executed by a processor, cause theprocessor to perform at least a portion of the methods described herein.Moreover, as used herein, the term “non-transitory computer-readablemedium” includes all tangible, computer-readable media, including,without limitation, non-transitory computer storage devices, including,without limitation, volatile and nonvolatile media, and removable andnon-removable media such as a firmware, physical and virtual storage,CD-ROMs, DVDs, and any other digital source such as a network or theInternet, as well as yet to be developed digital means, with the soleexception being a transitory, propagating signal.

The one or more memory devices 1108 may store information accessible bythe one or more processors 1106, including computer-executableinstructions 1110 that can be executed by the one or more processors1106. The instructions 1110 may include any set of instructions whichwhen executed by the one or more processors 1106 cause the one or moreprocessors 1106 to perform operations, including optical elementmonitoring operations, maintenance operations, cleaning operations,calibration operations, and/or additive manufacturing operations.

The memory devices 1108 may store data 1112 accessible by the one ormore processors 1106. The data 1112 can include current or real-timedata 1112, past data 1112, or a combination thereof. The data 1112 maybe stored in a data library 1114. As examples, the data 1112 may includedata 1112 associated with or generated by an additive manufacturingsystem 100 and/or an additive manufacturing machine 102, including data1112 associated with or generated by the controller 1100, an additivemanufacturing machine 102, an energy beam system 118, a monitoringsystem 254, a management system 106, a user interface 108, and/or acomputing device 1104. Such data 1112 may pertain to operation of one ormore build units 110 and/or one or more inertization systems 200. Thedata 1112 may also include other data sets, parameters, outputs,information, associated with an additive manufacturing system 100 and/oran additive manufacturing machine 102.

The one or more computing devices 1104 may also include a communicationinterface 1116, which may be used for communications with acommunication network 1118 via wired or wireless communication lines1120. The communication interface 1116 may include any suitablecomponents for interfacing with one or more network(s), including forexample, transmitters, receivers, ports, controllers, antennas, and/orother suitable components. The communication interface 1116 may allowthe computing device 1104 to communicate with various nodes on thecommunication network 1118, such as nodes associated with the additivemanufacturing machine 102, one or more build units 110, one or moreinertization systems 200, the management system 106, and/or a userinterface 108. The communication network 1118 may include, for example,a local area network (LAN), a wide area network (WAN), SATCOM network,VHF network, a HF network, a Wi-Fi network, a WiMAX network, a gatelinknetwork, and/or any other suitable communication network 1118 fortransmitting messages to and/or from the controller 1100 across thecommunication lines 1120. The communication lines 1120 of communicationnetwork 1118 may include a data bus or a combination of wired and/orwireless communication links.

The communication interface 1116 may allow the computing device 1104 tocommunicate with various components of an additive manufacturing system100 and/or an additive manufacturing machine 102 communicatively coupledwith the communication interface 1116 and/or communicatively coupledwith one another, including one or more build units 110 and/or one ormore inertization systems 200. The communication interface 1116 mayadditionally or alternatively allow the computing device 1104 tocommunicate with the management system 106 and/or the user interface108. The management system 106 may include a server 1122 and/or a datawarehouse 1124. As an example, at least a portion of the data 1112 maybe stored in the data warehouse 1124, and the server 1122 may beconfigured to transmit data 1112 from the data warehouse 1124 to thecomputing device 1104, and/or to receive data 1112 from the computingdevice 1104 and to store the received data 1112 in the data warehouse1124 for further purposes. The server 1122 and/or the data warehouse1124 may be implemented as part of a control system 104 and/or as partof the management system 106.

Now turning to FIG. 12, exemplary methods of additively manufacturingthree-dimensional objects will be described. As shown, an exemplarymethod 1200 may include, at block 1202, positioning a build unit 110above a region of a powder bed 227. The region of the powder bed 227 mayinclude a portion of the powder bed 227 intended to be irradiated.Positioning the build unit 110 may include moving the build unit 110,such as with a build unit-positioning system 124. Additionally, or inthe alternative, moving the build unit 110 may include moving a buildvessel 112 configured to support the powder bed 227 beneath the buildunit 110, for example, with a build vessel-positioning system 128. Thebuild unit 110 may include an energy beam system 118 and an inertizationsystem 200. The energy beam system 118 may include one or moreirradiation devices 216 respectively configured to direct one or moreenergy beams 214 onto a region of a powder bed 227 corresponding to arespective scan field 212 of the one or more energy beams 214. Theinertization system 200 may include an irradiation chamber 120 definingan irradiation plenum 121. The inertization system 200 may additionallyor alternatively include one or more supply manifolds 202 configured tosupply process gas to the irradiation plenum 121 and/or and a returnmanifold 204 configured to receive and/or evacuate process gas from theirradiation plenum.

An exemplary method 1200 may include, at block 1204, irradiating aregion of a powder bed 227 with the build unit 110 situated above theregion of the powder bed 227 intended to be irradiated. At block 1206,an exemplary method 1200 may include flowing process gas through the oneor more supply manifolds 202 and into the irradiation plenum 121 whileirradiating the powder bed 227. The one or more supply manifolds 202 mayinclude a downflow manifold 210 configured to provide a downward flow ofprocess gas through at least a portion of the irradiation plenum 121defined by the irradiation chamber 120. Additionally, or in thealternative, the one or more supply manifolds 202 may include acrossflow manifold 222 configured to provide a lateral flow of processgas through at least a portion of the irradiation plenum 121 defined bythe irradiation chamber 120.

Flowing process gas through the one or more supply manifolds 202 andinto the irradiation plenum 121 may include flowing process gas througha plurality of downflow manifold apertures 422 disposed within the oneor more inward downflow manifold walls 412. The plurality of downflowmanifold apertures 422 may fluidly communicate between one or moredownflow manifold pathways 418 and an optics plenum 235. The one or moredownflow manifold pathways 418 may be defined by the downflow manifoldbody 400. The downflow manifold body 400 may include one or more inwarddownflow manifold walls 412 defining the optics plenum 235. The opticsplenum may include a distal portion of the irradiation plenum 121relative to the powder bed 227. The plurality of plurality of downflowmanifold apertures 422 may be oriented parallel to a longitudinal axis424 of the downflow manifold body 400 or within 10 degrees of parallelto the longitudinal axis 424 of the downflow manifold body 400.

Additionally, or in the alternative, flowing process gas through the oneor more supply manifolds 202 and into the irradiation plenum 121 mayinclude transversely expanding the process gas at a transverse expansionregion 514 of respective ones of a plurality of crossflow manifoldbodies 500 of a crossflow manifold 222, followed by laterallytranslating the process gas at a lateral translation region 516 ofrespective ones of the plurality of crossflow manifold bodies 500. Thetransverse expansion region 514 may be located downstream from acrossflow manifold inlet 502 of a respective crossflow manifold body500. The lateral translation region 516 may be located downstream fromthe transverse expansion region 514 and upstream from a crossflowmanifold outlet 504 of the crossflow manifold 222. The transverseexpansion region 514 may exhibit a transverse expansion relative to alongitudinal axis 510 of the respective crossflow manifold inlet 502and/or relative to a lateral axis 512 of the crossflow manifold outlet504. The lateral translation region 516 may exhibit a lateraltranslation in an axial orientation of the respective crossflow manifoldbody 500 relative to the longitudinal axis 510 of the respectivecrossflow manifold inlet 502 and/or relative to a lateral axis 512 ofthe crossflow manifold outlet 504.

An exemplary method 1200 may include, at block 1208, evacuating processgas from the irradiation plenum 121 through a return manifold body 800while irradiating the powder bed 227. Evacuating process gas from theirradiation plenum 121 may include accelerating process gas flowing intoa return manifold inlet 802 of a return manifold 204 and/or through oneor more return manifold pathways 806 defined by a respective one or morereturn manifold bodies 800. The process gas may be accelerated by way ofa pressure reduction within the return manifold inlet 802 and/or withinthe one or more return manifold pathways 806. The pressure reduction maybe provided by one or more narrowing regions 821 and/or one or more ribelements 822 disposed about the return manifold inlet 802 and/or withinthe one or more return manifold pathways 806.

Further aspects of the presently disclosed subject matter are providedby the following clauses:

1. A build unit for additively manufacturing three-dimensional objects,the build unit comprising: an energy beam system, the energy beam systemcomprising one or more irradiation devices respectively configured todirect one or more energy beams onto a region of a powder bed; and aninertization system, the inertization system comprising an irradiationchamber defining an irradiation plenum, one or more supply manifolds,and a return manifold; wherein the one or more supply manifoldscomprises a downflow manifold configured to provide a downward flow of aprocess gas through at least a portion of the irradiation plenum definedby the irradiation chamber, and a crossflow manifold configured toprovide a lateral flow of the process gas through at least a portion ofthe irradiation plenum defined by the irradiation chamber.

2. The build unit of any clause herein, wherein the downflow manifold isconfigured and arranged to interchangeably accommodate a selected one ofa plurality of different energy beam systems, and/or to interchangeablyaccommodate a selected one of a plurality of different irradiationdevices and/or monitoring devices, and/or to interchangeably accommodatea selected one of a plurality of different optical elements that may beincluded in the selected one of a plurality of different irradiationdevices and/or monitoring devices.

3. The build unit of any clause herein, wherein the downflow manifoldcomprises one or more inward downflow manifold walls defining an opticsplenum configured to receive one or more irradiation devices; andwherein the optics plenum is configured and arranged to interchangeablyaccommodate a selected one of a plurality of different energy beamsystems, and/or to interchangeably accommodate a selected one of aplurality of different irradiation devices and/or monitoring devices,and/or to interchangeably accommodate a selected one of a plurality ofdifferent optical elements that may be included in the selected one of aplurality of different irradiation devices and/or monitoring devices.

4. The build unit of any clause herein, wherein the downflow manifoldcomprises a downflow manifold body defining one or more downflowmanifold pathways within the downflow manifold body.

5. The build unit of any clause herein, wherein the downflow manifoldbody comprises one or more inward downflow manifold walls, the one ormore inward downflow manifold walls defining an optics plenum coincidingwith a distal portion of the irradiation plenum relative to the powderbed.

6. The build unit of any clause herein, wherein the one or more inwarddownflow manifold walls diverge from a longitudinal axis of the downflowmanifold body in a proximal direction relative to the powder bed at adivergence angle allowing the one or more energy beams from the energybeam system to access the portion of the powder bed corresponding to ascan field of the one or more energy beams.

7. The build unit of any clause herein, wherein the one or more inwarddownflow manifold walls comprise a plurality of downflow manifoldapertures oriented parallel to a longitudinal axis of the downflowmanifold body or within 10 degrees of parallel to the longitudinal axisof the downflow manifold body.

8. The build unit of any clause herein, wherein the crossflow manifoldcomprises a plurality of crossflow manifold bodies arranged along awidth of the crossflow manifold, the plurality of crossflow manifoldbodies respectively coupled to one another or defining a respectiveintegrally formed portion of the crossflow manifold.

9. The build unit of any clause herein, wherein, respective ones of theplurality of crossflow manifold bodies comprise a crossflow manifoldinlet fluidly communicating with a process gas supply line and aplurality of crossflow manifold pathways defined by the respective oneof the plurality of crossflow manifold bodies.

10. The build unit of any clause herein, wherein the crossflow manifoldcomprises a crossflow manifold outlet defined at least in part byrespective ones of the plurality of crossflow manifold bodies, thecrossflow manifold outlet fluidly communicating with the irradiationplenum defined by the irradiation chamber and the plurality of crossflowmanifold pathways of the respective ones of the plurality of crossflowmanifold bodies.

11. The build unit of any clause herein, wherein the crossflow manifoldoutlet has an elongate cross-sectional profile, and wherein respectiveones of the plurality of crossflow manifold bodies comprise a transverseexpansion region and a lateral translation region, the transverseexpansion region exhibiting a transverse expansion of the respectivecrossflow manifold body relative to a longitudinal axis of therespective crossflow manifold inlet and/or relative to a lateral axis ofthe crossflow manifold outlet, and the lateral translation regionexhibiting a lateral translation in an axial orientation of therespective crossflow manifold body relative to the longitudinal axis ofthe respective crossflow manifold inlet and/or relative to a lateralaxis of the crossflow manifold outlet.

12. The build unit of any clause herein, wherein the transverseexpansion region is located downstream from the respective crossflowmanifold inlet, and the lateral translation region located downstreamfrom the transverse expansion region and upstream from the crossflowmanifold outlet.

13. The build unit of any clause herein, wherein the return manifold isconfigured to receive and/or evacuate process gas from the irradiationplenum while irradiating a powder bed, the process gas flowing throughthe irradiation plenum and into the return manifold.

14. The build unit of any clause herein, wherein the return manifoldcomprises a plurality of evacuation manifold bodies arranged along awidth of the return manifold, the plurality of evacuation manifoldbodies respectively coupled to one another or defining a respectiveintegrally formed portion of the return manifold.

15. The build unit of any clause herein, wherein the return manifoldcomprises a return manifold inlet and one or more evacuation manifoldpathways defined at least in part by respective ones of the plurality ofevacuation manifold bodies, the return manifold inlet fluidlycommunicating with the irradiation plenum defined by the irradiationchamber and the one or more evacuation manifold pathways defined by therespective ones of the plurality of evacuation manifold bodies.

16. The build unit of any clause herein, wherein respective ones of theplurality of evacuation manifold bodies comprise a return manifoldoutlet fluidly communicating with the one or more evacuation manifoldpathways of the respective evacuation manifold body and a process gasevacuation line.

17. The build unit of any clause herein, wherein the return manifoldinlet has an elongate cross-sectional profile, and wherein the returnmanifold comprises one or more narrowing regions and/or one or more ribelements disposed about the return manifold inlet and/or within the oneor more evacuation manifold pathways.

18. The build unit of any clause herein, wherein the one or morenarrowing regions and/or the one or more rib elements are configured toprovide a pressure reduction within the return manifold inlet and/orwithin the one or more evacuation manifold pathways, the pressurereduction accelerating the process gas flowing into the return manifoldinlet and/or through the one or more evacuation manifold pathways.

19. The build unit of any clause herein, wherein the return manifold isconfigured to receive a lateral flow of the process gas from at least aportion of an irradiation plenum defined by the irradiation chamber.

20. A build unit for additively manufacturing three-dimensional objects,the build unit comprising: an energy beam system, the energy beam systemcomprising one or more irradiation devices respectively configured todirect one or more energy beams onto a region of a powder bed; and aninertization system, the inertization system comprising an irradiationchamber defining an irradiation plenum and one or more supply manifoldsconfigured to supply a process gas to the irradiation plenum whileirradiating the region of the powder bed with the build unit situatedabove the region of the powder bed, the process gas flowing through theone or more supply manifolds and into the irradiation plenum whileirradiating the region of the powder bed; wherein the one or more supplymanifolds comprises a downflow manifold configured to provide a downwardflow of the process gas through at least a portion of the irradiationplenum defined by the irradiation chamber; wherein the downflow manifoldcomprises a downflow manifold body defining one or more downflowmanifold pathways within the downflow manifold body, the downflowmanifold body comprising one or more inward downflow manifold wallsdefining an optics plenum coinciding with a distal portion of theirradiation plenum relative to the powder bed; and wherein the one ormore inward downflow manifold walls diverge from a longitudinal axis ofthe downflow manifold body in a proximal direction relative to thepowder bed at a divergence angle allowing the one or more energy beamsof the energy beam system to access the portion of the powder bedcorresponding to a scan field of the one or more energy beams; whereinthe one or more inward downflow manifold walls comprise a plurality ofdownflow manifold apertures fluidly communicating between the opticsplenum and one or more downflow manifold pathways defined by thedownflow manifold body, the plurality of downflow manifold aperturesoriented parallel to a longitudinal axis of the downflow manifold bodyor within 10 degrees of parallel to the longitudinal axis of thedownflow manifold body.

21. The build unit of any clause herein, wherein the one or more inwarddownflow manifold walls comprise a second plurality of plurality ofdownflow manifold apertures oriented oblique and/or perpendicular to thelongitudinal axis of the downflow manifold body.

22. The build unit of any clause herein, comprising: an optics windowseparating one or more optical elements of the energy beam system fromthe optics plenum, the optics window defining a top portion of theoptics plenum.

23. The build unit of any clause herein, wherein the downflow manifoldand/or the optics plenum are configured and arranged to interchangeablyaccommodate a plurality of different energy beam systems, and/or tointerchangeably accommodate a plurality of different irradiation devicesand/or monitoring devices, and/or to interchangeably accommodate aplurality of different optical elements that may be included in anirradiation device or a measurement device.

24. The build unit of any clause herein, wherein the irradiation plenumhas an elongate cross-sectional surface area configured to accommodate aplurality of adjacently disposed optical elements utilized by the energybeam system.

25. The build unit of any clause herein, wherein the downflow manifoldbody comprises one or more bottom downflow manifold walls defining adistal portion of the irradiation plenum relative to the powder bed; andwherein the one or more bottom downflow manifold walls comprise a secondplurality of downflow manifold apertures fluidly communicating betweenthe irradiation plenum and the one or more downflow manifold pathwaysdefined by the downflow manifold body, the plurality of downflowmanifold apertures oriented parallel to a longitudinal axis of thedownflow manifold body or within 10 degrees of parallel to thelongitudinal axis of the downflow manifold body.

26. The build unit of any clause herein, wherein the one or more bottomdownflow manifold walls comprise a third plurality of plurality ofdownflow manifold apertures oriented oblique and/or perpendicular to thelongitudinal axis of the downflow manifold body.

27. The build unit of any clause herein, wherein the downflow manifoldbody comprises one or more downflow manifold baffles disposed within theone or more downflow manifold pathways.

28. The build unit of any clause herein, wherein the energy beam systemcomprises an energy beam housing, the energy beam housing coupled to thedownflow manifold and/or the energy beam housing defining a portion ofthe downflow manifold.

29. The build unit of any clause herein, wherein the irradiation chambercomprises one or more downflow walls may be oriented parallel and/oroblique to a longitudinal axis of the irradiation chamber.

30. The build unit of any clause herein, comprising: a supply manifoldheader, the supply manifold header configured to distribute the processgas to the one or more supply manifolds, the supply manifold headercomprising a plurality of supply manifold distribution elements.

31. The build unit of any clause herein, wherein the supply manifoldheader comprises one or more supply header conjunction elements, the oneor more supply header conjunction elements providing fluid communicationbetween at least some of the plurality of supply manifold distributionelements.

32. The build unit of any clause herein, wherein the one or more supplymanifolds comprises a crossflow manifold configured to provide a lateralflow of the process gas through at least a portion of the irradiationplenum defined by the irradiation chamber.

33. The build unit of any clause herein, comprising: a return manifoldconfigured to receive and/or evacuate the process gas from theirradiation plenum.

34. A build unit for additively manufacturing three-dimensional objects,the build unit comprising: an energy beam system, the energy beam systemcomprising one or more irradiation devices respectively configured todirect one or more energy beams onto a region of a powder bed; and aninertization system, the inertization system comprising an irradiationchamber defining an irradiation plenum and one or more supply manifoldsconfigured to supply a process gas to the irradiation plenum whileirradiating the region of the powder bed with the build unit situatedabove the region of the powder bed, the process gas flowing through theone or more supply manifolds and into the irradiation plenum whileirradiating the region of the powder bed; wherein the one or more supplymanifolds comprises a crossflow manifold configured to provide a lateralflow of the process gas through at least a portion of the irradiationplenum defined by the irradiation chamber; wherein the crossflowmanifold comprises a plurality of crossflow manifold bodies arrangedalong a width of the crossflow manifold, the plurality of crossflowmanifold bodies respectively coupled to one another or defining arespective integrally formed portion of the crossflow manifold,respective ones of the plurality of crossflow manifold bodies comprisinga crossflow manifold inlet fluidly communicating with a process gassupply line and a plurality of crossflow manifold pathways defined bythe respective crossflow manifold body, and the crossflow manifoldcomprising a crossflow manifold outlet defined at least in part byrespective ones of the plurality of crossflow manifold bodies, thecrossflow manifold outlet fluidly communicating with the irradiationplenum defined by the irradiation chamber and the plurality of crossflowmanifold pathways of the respective ones of the plurality of crossflowmanifold bodies; and wherein the crossflow manifold outlet has anelongate cross-sectional profile, and wherein respective ones of theplurality of crossflow manifold bodies comprise a transverse expansionregion and a lateral translation region, the transverse expansion regionlocated downstream from the respective crossflow manifold inlet, and thelateral translation region located downstream from the transverseexpansion region and upstream from the crossflow manifold outlet, thetransverse expansion region exhibiting a transverse expansion of therespective crossflow manifold body relative to a longitudinal axis ofthe respective crossflow manifold inlet and/or relative to a lateralaxis of the crossflow manifold outlet, and the lateral translationregion exhibiting a lateral translation in an axial orientation of therespective crossflow manifold body relative to the longitudinal axis ofthe respective crossflow manifold inlet and/or relative to a lateralaxis of the crossflow manifold outlet.

35. The build unit of any clause herein, wherein the crossflow manifoldcomprises a plurality of crossflow manifold pathway walls, the pluralityof crossflow manifold pathway walls respectively defining at least aportion of respective ones of the plurality of crossflow manifoldpathways.

36. The build unit of any clause herein, wherein respective ones of theplurality of crossflow manifold bodies comprise a longitudinal extensionregion disposed between at least a portion of the transverse expansionregion and at least a portion of the lateral translation region, thelongitudinal extension region exhibiting a longitudinal extension in therespective crossflow manifold body relative to the longitudinal axis ofthe respective crossflow manifold inlet.

37. The build unit of any clause herein, wherein respective ones of theplurality of crossflow manifold bodies comprise a lateral profilingregion coinciding with a location of at least a portion of thetransverse expansion region and/or at least a portion of the lateraltranslation region, the lateral profiling region exhibiting a lateralchange in cross-sectional profile of the respective crossflow manifoldbody relative to a cross-sectional profile of the respective crossflowmanifold inlet.

38. The build unit of any clause herein, wherein the crossflow manifoldcomprises a plurality of inlet flow conditioners, respective ones of theplurality of inlet flow conditioners disposed in a respective crossflowmanifold inlet.

39. The build unit of any clause herein, wherein respective ones of theplurality of inlet flow conditioners comprise a lattice defining aplurality of inlet flow conditioning channels, respective ones of theplurality of inlet flow conditioning channels comprising a polygonalcross-sectional profile, an elliptical cross-sectional profile, and/or acurvilinear cross-sectional profile.

40. The build unit of any clause herein, wherein respective ones of theplurality of inlet flow conditioners are removably and/or fixedlyinserted within the respective crossflow manifold inlet, or whereinrespective ones of the plurality of inlet flow conditioners areintegrally formed as part of the respective crossflow manifold bodydefining the respective crossflow manifold inlet.

41. The build unit of any clause herein, wherein the crossflow manifoldcomprises an outlet flow conditioner disposed in the crossflow manifoldoutlet.

42. The build unit of any clause herein, wherein the outlet flowconditioner comprises a lattice defining a plurality of outlet flowconditioning channels, respective ones of the plurality of outlet flowconditioning channels comprising a polygonal cross-sectional profile, anelliptical cross-sectional profile, and/or a curvilinear cross-sectionalprofile.

43. The build unit of any clause herein, wherein at least some of theplurality of outlet flow conditioning channels have an obliqueorientation that converges towards a lateral axis of the crossflowmanifold outlet in a direction of a flow of process gas through theplurality of outlet flow conditioning channels.

44. The build unit of any clause herein, wherein at least some of theplurality of outlet flow conditioning channels are oriented relative toa normal line perpendicular to a tangent of a curvilinear plane, thecurvilinear plane corresponding to a portion of a sphere or an ovoid.

45. The build unit of any clause herein, wherein the outlet flowconditioner is removably and/or fixedly inserted within the crossflowmanifold outlet, or wherein the outlet flow conditioner is integrallyformed as part of the plurality of crossflow manifold bodies definingthe crossflow manifold outlet.

46. The build unit of any clause herein, wherein the plurality ofcrossflow manifold bodies comprises one or more crossflow manifoldsidewalls with an outlet flow conditioner access port configured toreceive the outlet flow conditioner.

47. The build unit of any clause herein, wherein the plurality ofcrossflow manifold bodies comprises one or more outlet flow conditionerslots configured to receive an outflow conditioner, the one or moreoutlet flow conditioner slots extending transversely across theplurality of crossflow manifold bodies adjacent to and/or upstream fromthe crossflow manifold outlet.

48. The build unit of any clause herein, comprising: a supply manifoldheader configured to distribute process gas to the one or more supplymanifolds; and a plurality of process gas supply lines, respective onesof the process gas supply lines fluidly communicating between the supplymanifold header and the respective crossflow manifold inlet.

49. The build unit of any clause herein, comprising: one or more supplyheader conjunction elements, respective ones of the one or more supplyheader conjunction elements fluidly communicating between a respectivefirst and second ones of the plurality of process gas supply lines, theone or more supply header conjunction elements configured to allow aflow of process gas to distribute proportionally between the pluralityof process gas supply lines.

50. The build unit of any clause herein, wherein the inertization systemcomprises a return manifold configured to receive and/or evacuateprocess gas from the irradiation plenum while irradiating the region ofthe powder bed with the build unit situated above the region of thepowder bed, the process gas flowing through the irradiation plenum andinto the return manifold while irradiating the region of the powder bed.

51. The build unit of any clause herein, wherein the one or more supplymanifolds comprises a downflow manifold configured to provide a downwardflow of the process gas through at least a portion of the irradiationplenum defined by the irradiation chamber.

52. The build unit of any clause herein, wherein the irradiation chambercomprises a crossflow chamber defining a crossflow plenum occupying atleast a portion of the irradiation plenum, wherein the crossflowmanifold is configured to provide a lateral flow of the process gasthrough the crossflow plenum, and wherein the crossflow chambercomprises one or more crossflow walls oriented parallel or oblique to alateral axis of the crossflow chamber.

53. A build unit for additively manufacturing three-dimensional objects,the build unit comprising: an energy beam system, the energy beam systemcomprising one or more irradiation devices respectively configured todirect one or more energy beams onto a region of a powder bed; and aninertization system, the inertization system comprising an irradiationchamber defining an irradiation plenum and a return manifold configuredto receive and/or evacuate a process gas from the irradiation plenumwhile irradiating the region of the powder bed with the build unitsituated above the region of the powder bed, the process gas flowingthrough the irradiation plenum and into the return manifold whileirradiating the region of the powder bed; wherein the return manifoldcomprises a plurality of return manifold bodies arranged along a widthof the return manifold, the plurality of return manifold bodiesrespectively coupled to one another or defining a respective integrallyformed portion of the return manifold, the return manifold comprising areturn manifold inlet defined at least in part by respective ones of theplurality of return manifold bodies, respective ones of the plurality ofreturn manifold bodies comprising one or more return manifold pathwaysand a return manifold outlet fluidly communicating with the one or morereturn manifold pathways of the return manifold body and a process gasevacuation line, and the return manifold inlet fluidly communicatingwith the irradiation plenum defined by the irradiation chamber and theone or more return manifold pathways defined by the respective ones ofthe plurality of return manifold bodies; wherein the return manifold isconfigured to receive a lateral flow of the process gas from at least aportion of an irradiation plenum defined by the irradiation chamber,wherein the return manifold inlet has an elongate cross-sectionalprofile, and wherein the return manifold comprises one or more narrowingregions and/or one or more rib elements disposed about the returnmanifold inlet and/or within the one or more return manifold pathways.

54. The build unit of any clause herein, wherein the plurality of returnmanifold bodies comprises one or more recapture pathways disposed abouta bottom portion of the one or more return manifold pathways, the one ormore recapture pathways configured to receive the process gas into theone or more return manifold pathways that flows past the return manifoldinlet.

55. The build unit of any clause herein, wherein the one or morerecapture pathways comprise an elongate slit disposed transverselyacross a bottom portion of the one or more return manifold pathways.

56. The build unit of any clause herein, wherein the one or morerecapture pathways fluidly communicate with the one or more returnmanifold pathways downstream from an inlet edge of a return manifoldinlet.

57. The build unit of any clause herein, wherein the one or morerecapture pathways fluidly communicate with the one or more returnmanifold pathways upstream from at least one of the one or morenarrowing elements and/or from at least one of the one or more ribelements.

58. The build unit of any clause herein, wherein the one or morerecapture pathways comprise a slit, an array of perforations, a lattice,or a grating, the one or more recapture pathways disposed about at leasta portion of the one or more return manifold pathways.

59. The build unit of any clause herein, wherein respective ones of theplurality of the return manifold bodies comprise an upward translationregion located downstream from the return manifold inlet, the upwardtranslation region exhibiting an upward translation in an axialorientation of the respective crossflow manifold body relative to alongitudinal axis of the respective crossflow manifold inlet and/orrelative to a lateral axis of the respective return manifold outlet.

60. The build unit of any clause herein, wherein respective ones of theplurality of the return manifold bodies comprise a transversecontraction region located downstream from the respective upwardtranslation region and upstream from the respective return manifoldoutlet, the transverse contraction region exhibiting a transversecontraction in the respective return manifold body relative to a lateralaxis of the return manifold inlet and/or relative to a longitudinal axisof the respective return manifold outlet.

61. The build unit of any clause herein, wherein respective ones of theplurality of the return manifold bodies comprise a lateral profilingregion coinciding with a location of at least a portion of thetransverse contraction region and/or at least a portion of the upwardtranslation region, the lateral profiling region exhibiting a lateralchange in cross-sectional profile of the respective return manifold bodyrelative to a cross-sectional profile of the respective crossflowmanifold inlet.

62. The build unit of any clause herein, wherein respective ones of theplurality of return manifold bodies comprises a longitudinal extensionregion disposed between at least a portion of the upward translationregion and at least a portion of the transverse contraction region, thelongitudinal extension region exhibiting a longitudinal extension of therespective return manifold body relative to the longitudinal axis of therespective return manifold outlet.

63. The build unit of any clause herein, wherein the inertization systemcomprises: one or more supply manifolds configured to supply the processgas to the irradiation plenum while irradiating the region of the powderbed with the build unit situated above the region of the powder bed, theprocess gas flowing through the one or more supply manifolds and intothe irradiation plenum while irradiating the region of the powder bed.

64. The build unit of any clause herein, wherein the one or more supplymanifolds comprises a crossflow manifold configured to provide a lateralflow of the process gas through at least a portion of the irradiationplenum defined by the irradiation chamber.

65. The build unit of any clause herein, wherein the one or more supplymanifolds comprises a downflow manifold configured to provide a downwardflow of the process gas through at least a portion of the irradiationplenum defined by the irradiation chamber.

66. The build unit of any clause herein, wherein the return manifold isconfigured to receive the lateral flow of the process gas from thecrossflow manifold and/or the downward flow of the process from thedownflow manifold.

67. The build unit of any clause herein, wherein the irradiation chambercomprises a crossflow chamber defining a crossflow plenum occupying atleast a portion of the irradiation plenum, wherein the crossflowmanifold is configured to provide a lateral flow of the process gasthrough the crossflow plenum, and wherein the crossflow chambercomprises one or more crossflow walls oriented parallel or oblique to alateral axis of the crossflow chamber.

68. The build unit of any clause herein, wherein respective ones of theone or more crossflow walls comprise: one or more flanges havingattachment points configured to couple the respective crossflow wall toa crossflow manifold, to a return manifold, and/or to a downflow wall ofthe irradiation chamber; and one or more bevels, respective ones of theone or more bevels disposed between a face of the respective crossflowwall and respective ones of the one or more flanges, respective ones ofthe one or more bevels sloping away from the one of the one or moreflanges.

69. The build unit of any clause herein, wherein the irradiation chambercomprises a downflow chamber defining a downflow plenum occupying atleast a portion of the irradiation plenum, wherein the downflow manifoldis configured to provide a downward flow of the process gas through thedownflow plenum, and wherein the downflow chamber comprises one or moredownflow walls oriented parallel or oblique to a longitudinal axis ofthe downflow chamber.

70. An additive manufacturing system, comprising: a build unit; a buildvessel; a build unit-positioning system and/or a buildvessel-positioning system; and wherein the build unit comprises: anenergy beam system, the energy beam system comprising one or moreirradiation devices respectively configured to direct one or more energybeams onto a region of a powder bed; and an inertization system, theinertization system comprising an irradiation chamber defining anirradiation plenum, one or more supply manifolds, and a return manifold;wherein the one or more supply manifolds comprises a downflow manifoldconfigured to provide a downward flow of a process gas through at leasta portion of the irradiation plenum defined by the irradiation chamber,and a crossflow manifold configured to provide a lateral flow of aprocess gas through at least a portion of the irradiation plenum definedby the irradiation chamber.

71. The additive manufacturing system of any clause herein, wherein thebuild unit-positioning system is configured to move the build unit tospecified build coordinates and/or along specified build vectors.

72. The additive manufacturing system of any clause herein, wherein thebuild vessel-positioning system is configured to move the build vesselto specified build coordinates and/or along specified build vectors.

73. The additive manufacturing system of any clause herein, comprising:

a control system configured to control one or more operations of theadditive manufacturing system.

74. The additive manufacturing system of any clause herein, comprisingthe build unit of any clause herein.

75. A method of additively manufacturing a three-dimensional object, themethod comprising: irradiating a powder bed with a build unit situatedabove a powder bed, the build unit comprising an energy beam system andan inertization system, wherein the inertization system comprises: anirradiation chamber defining an irradiation plenum, one or more supplymanifolds configured to supply process gas to the irradiation plenum,and a return manifold configured to receive and/or evacuate process gasfrom the irradiation plenum; flowing a process gas through the one ormore supply manifolds and into the irradiation plenum while irradiatingthe powder bed, wherein the one or more supply manifolds comprises adownflow manifold configured to provide a downward flow of the processgas through at least a portion of the irradiation plenum defined by theirradiation chamber, and a crossflow manifold configured to provide alateral flow of the process gas through at least a portion of theirradiation plenum defined by the irradiation chamber; and evacuatingthe process gas from the irradiation plenum through the return manifoldwhile irradiating the powder bed.

76. The method of any clause herein, wherein flowing the process gasthrough the one or more supply manifolds and into the irradiation plenumcomprises flowing the process gas through a plurality of downflowmanifold apertures disposed within one or more inward downflow manifoldwalls of the downflow manifold.

77. The method of any clause herein, wherein flowing the process gasthrough the one or more supply manifolds and into the irradiation plenumcomprises transversely expanding the process gas at a transverseexpansion region of respective ones of a plurality of crossflow manifoldbodies followed by laterally translating the process gas at a lateraltranslation region of respective ones of the plurality of crossflowmanifold bodies, the transverse expansion region located downstream fromthe respective crossflow manifold inlet, and the lateral translationregion located downstream from the transverse expansion region andupstream from a crossflow manifold outlet, the transverse expansionregion exhibiting a transverse expansion relative to a longitudinal axisof the respective crossflow manifold inlet and/or relative to a lateralaxis of the crossflow manifold outlet, and the lateral translationregion exhibiting a lateral translation in an axial orientation of therespective crossflow manifold body relative to the longitudinal axis ofthe respective crossflow manifold inlet and/or relative to a lateralaxis of the crossflow manifold outlet.

78. The method of any clause herein, wherein evacuating the process gasfrom the irradiation plenum comprises accelerating process gas flowinginto a return manifold inlet and/or through one or more evacuationmanifold pathways by way of a pressure reduction within the returnmanifold inlet and/or within the one or more evacuation manifoldpathways, the pressure reduction provided by one or more narrowingregions and/or one or more rib elements disposed about the returnmanifold inlet and/or within the one or more evacuation manifoldpathways.

79. A method of additively manufacturing a three-dimensional object, themethod comprising: irradiating a region of a powder bed with a buildunit situated above the region of the powder bed, the build unitcomprising an energy beam system and an inertization system, the energybeam system comprising one or more irradiation devices respectivelyconfigured to direct one or more energy beams onto a region of a powderbed, and the inertization system comprising an irradiation chamberdefining an irradiation plenum and one or more supply manifoldsconfigured to supply process gas to the irradiation plenum; and flowinga process gas through the one or more supply manifolds and into theirradiation plenum while irradiating the powder bed, wherein the one ormore supply manifolds comprises a downflow manifold configured toprovide a downward flow of the process gas through at least a portion ofthe irradiation plenum defined by the irradiation chamber; wherein thedownflow manifold comprises a downflow manifold body defining one ormore downflow manifold pathways within the downflow manifold body, thedownflow manifold body comprising one or more inward downflow manifoldwalls defining an optics plenum comprising a distal portion of theirradiation plenum relative to the powder bed; and wherein the one ormore inward downflow manifold walls diverge from a longitudinal axis ofthe downflow manifold body in a proximal direction relative to thepowder bed at a divergence angle allowing the one or more energy beamsof the energy beam system to access the portion of the powder bedcorresponding to a scan field of the one or more energy beams; whereinflowing process gas through the one or more supply manifolds and intothe irradiation plenum comprises flowing the process gas through aplurality of downflow manifold apertures disposed within the one or moreinward downflow manifold walls, the plurality of downflow manifoldapertures fluidly communicating between the optics plenum and the one ormore downflow manifold pathways defined by the downflow manifold body,the plurality of downflow manifold apertures oriented parallel to alongitudinal axis of the downflow manifold body or within 10 degrees ofparallel to the longitudinal axis of the downflow manifold body.

80. The method of any clause herein, comprising: positioning the buildunit above the region of a powder bed at least in part by moving thebuild unit with a build unit-positioning system and/or by moving a buildvessel configured to support the powder bed beneath the build unit, thebuild vessel moved at least in part by a build vessel-positioningsystem.

81. The method of any clause herein, wherein the irradiation plenumcomprises a downflow plenum, the downward flow of the process gasflowing through the downflow plenum, wherein the downward flow of theprocess gas comprises a primary downflow flow field and a quiescentdownflow flow field at least partially surrounded by the primarydownflow flow field, the primary downflow flow field occupying anannular or semiannular region extending longitudinally below at least aportion of the downflow manifold, and the quiescent downflow flow fieldoccupying at least a portion of the optics plenum.

82. The method of any clause herein, wherein flowing the process gasthrough the one or more supply manifolds and into the irradiation plenumcomprises flowing the process gas through a crossflow manifoldconfigured to provide a lateral flow of the process gas through at leasta portion of the irradiation plenum defined by the irradiation chamber.

83. The method of any clause herein, wherein the irradiation plenumcomprises a crossflow plenum, wherein the lateral flow of the processgas flowing through the crossflow plenum has a lateral velocity thatexceeds a downward velocity of the downward flow of the process gasflowing through the irradiation plenum.

84. The method of any clause herein, comprising:

evacuating the process gas from the irradiation plenum through a returnmanifold while irradiating the powder bed.

85. A method of additively manufacturing a three-dimensional object, themethod comprising: irradiating a region of a powder bed with a buildunit situated above the region of the powder bed, the build unitcomprising an energy beam system and an inertization system, the energybeam system comprising one or more irradiation devices respectivelyconfigured to direct one or more energy beams onto a region of a powderbed, and the inertization system comprising an irradiation chamberdefining an irradiation plenum and one or more supply manifoldsconfigured to supply process gas to the irradiation plenum; and flowinga process gas through the one or more supply manifolds and into theirradiation plenum while irradiating the powder bed, wherein the one ormore supply manifolds comprises a crossflow manifold configured toprovide a lateral flow of the process gas through at least a portion ofthe irradiation plenum defined by the irradiation chamber; wherein thecrossflow manifold comprises a plurality of crossflow manifold bodiesarranged along a width of the crossflow manifold, the plurality ofcrossflow manifold bodies respectively coupled to one another ordefining a respective integrally formed portion of the crossflowmanifold, respective ones of the plurality of crossflow manifold bodiescomprising a crossflow manifold inlet fluidly communicating with aprocess gas supply line and a plurality of crossflow manifold pathwaysdefined by the respective crossflow manifold body, and the crossflowmanifold comprising a crossflow manifold outlet defined at least in partby respective ones of the plurality of crossflow manifold bodies, thecrossflow manifold outlet having an elongate cross-sectional profile,and the crossflow manifold outlet fluidly communicating with theirradiation plenum defined by the irradiation chamber and the pluralityof crossflow manifold pathways of the respective ones of the pluralityof crossflow manifold bodies; wherein flowing the process gas throughthe one or more supply manifolds and into the irradiation plenumcomprises transversely expanding the process gas at a transverseexpansion region of respective ones of the plurality of crossflowmanifold bodies followed by laterally translating the process gas at alateral translation region of respective ones of the plurality ofcrossflow manifold bodies, the transverse expansion region locateddownstream from the respective crossflow manifold inlet, and the lateraltranslation region located downstream from the transverse expansionregion and upstream from the crossflow manifold outlet, the transverseexpansion region exhibiting a transverse expansion relative to alongitudinal axis of the respective crossflow manifold inlet and/orrelative to a lateral axis of the crossflow manifold outlet, and thelateral translation region exhibiting a lateral translation in an axialorientation of the respective crossflow manifold body relative to thelongitudinal axis of the respective crossflow manifold inlet and/orrelative to a lateral axis of the crossflow manifold outlet.

86. A method of additively manufacturing a three-dimensional object, themethod comprising: irradiating a region of a powder bed with a buildunit situated above the region of the powder bed, the build unitcomprising an energy beam system and an inertization system, the energybeam system comprising one or more irradiation devices respectivelyconfigured to direct one or more energy beams onto a region of a powderbed, and the inertization system comprising an irradiation chamberdefining an irradiation plenum and a return manifold configured toreceive and/or evacuate a process gas from the irradiation plenum; andevacuating the process gas from the irradiation plenum through thereturn manifold while irradiating the powder bed, wherein the returnmanifold comprises a plurality of return manifold bodies arranged alonga width of the return manifold, the plurality of return manifold bodiesrespectively coupled to one another or defining a respective integrallyformed portion of the return manifold, the return manifold comprising areturn manifold inlet defined at least in part by respective ones of theplurality of return manifold bodies, respective ones of the plurality ofreturn manifold bodies comprising one or more return manifold pathwaysand a return manifold outlet fluidly communicating with the one or morereturn manifold pathways of the respective return manifold body and aprocess gas evacuation line, the return manifold inlet having anelongate cross-sectional profile, and the return manifold inlet fluidlycommunicating with the irradiation plenum defined by the irradiationchamber and the one or more return manifold pathways defined by therespective ones of the plurality of return manifold bodies; whereinevacuating the process gas from the irradiation plenum comprisesaccelerating the process gas flowing into the return manifold inletand/or through the one or more return manifold pathways by way of apressure reduction within the return manifold inlet and/or within theone or more return manifold pathways, the pressure reduction provided byone or more narrowing regions and/or one or more rib elements disposedabout the return manifold inlet and/or within the one or more returnmanifold pathways.

87. The method of any clause herein, comprising: flowing the process gasthrough the one or more supply manifolds and into the irradiation plenumwhile irradiating the powder bed, wherein the one or more supplymanifolds comprises a downflow manifold configured to provide a downwardflow of the process gas through at least a portion of the irradiationplenum defined by the irradiation chamber, and a crossflow manifoldconfigured to provide a lateral flow of the process gas through at leasta portion of the irradiation plenum defined by the irradiation chamber.

88. The method of any clause herein, comprising: positioning the buildunit above the region of a powder bed at least in part by moving thebuild unit with a build unit-positioning system and/or by moving a buildvessel configured to support the powder bed beneath the build unit, thebuild vessel moved at least in part by a build vessel-positioningsystem; and wherein evacuating the process gas from the irradiationplenum through the return manifold while irradiating the powder bedcomprises evacuating the lateral flow of the process gas and thedownward flow of the process gas through the return manifold.

89. The method of any clause herein, wherein the method is performedusing the additive manufacturing system of any clause herein, and/orwherein the method is performed using the build unit of any clauseherein.

90. A computer-readable medium comprising computer-executableinstructions, which when executed by a processor associated with anadditive manufacturing machine, cause the additive manufacturing machineto perform a method of additively manufacturing a three-dimensionalobject, the method comprising: irradiating a powder bed with a buildunit situated above a powder bed, the build unit comprising an energybeam system and an inertization system, wherein the inertization systemcomprises: an irradiation chamber defining an irradiation plenum, one ormore supply manifolds configured to supply process gas to theirradiation plenum, and a return manifold configured to receive and/orevacuate process gas from the irradiation plenum; flowing a process gasthrough the one or more supply manifolds and into the irradiation plenumwhile irradiating the powder bed, wherein the one or more supplymanifolds comprises a downflow manifold configured to provide a downwardflow of the process gas through at least a portion of the irradiationplenum defined by the irradiation chamber, and a crossflow manifoldconfigured to provide a lateral flow of the process gas through at leasta portion of the irradiation plenum defined by the irradiation chamber;and evacuating process gas from the irradiation plenum through thereturn manifold while irradiating the powder bed. The computer-readablemedium may be configured to cause the additive manufacturing machine toperform the method of any clause herein.

This written description uses exemplary embodiments to describe thepresently disposed subject matter, including the best mode, and also toenable any person skilled in the art to practice such subject matter,including making and using any devices or systems and performing anyincorporated methods. The patentable scope of the presently disposedsubject matter is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they include structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

What is claimed is:
 1. A build unit for additively manufacturingthree-dimensional objects, the build unit comprising: an energy beamsystem, the energy beam system comprising one or more irradiationdevices respectively configured to direct one or more energy beams ontoa region of a powder bed; and an inertization system, the inertizationsystem comprising an irradiation chamber defining an irradiation plenumand one or more supply manifolds configured to supply a process gas tothe irradiation plenum while irradiating the region of the powder bedwith the build unit situated above the region of the powder bed, theprocess gas flowing through the one or more supply manifolds and intothe irradiation plenum while irradiating the region of the powder bed;wherein the one or more supply manifolds comprises a crossflow manifoldconfigured to provide a lateral flow of the process gas through at leasta portion of the irradiation plenum defined by the irradiation chamber;wherein the crossflow manifold comprises a plurality of crossflowmanifold bodies arranged along a width of the crossflow manifold, theplurality of crossflow manifold bodies respectively coupled to oneanother or defining a respective integrally formed portion of thecrossflow manifold, respective ones of the plurality of crossflowmanifold bodies comprising a crossflow manifold inlet fluidlycommunicating with a process gas supply line and a plurality ofcrossflow manifold pathways defined by the respective crossflow manifoldbody, and the crossflow manifold comprising a crossflow manifold outletdefined at least in part by respective ones of the plurality ofcrossflow manifold bodies, the crossflow manifold outlet fluidlycommunicating with the irradiation plenum defined by the irradiationchamber and the plurality of crossflow manifold pathways of therespective ones of the plurality of crossflow manifold bodies; andwherein the crossflow manifold outlet has an elongate cross-sectionalprofile, and wherein respective ones of the plurality of crossflowmanifold bodies comprise a transverse expansion region and a lateraltranslation region, the transverse expansion region located downstreamfrom the respective crossflow manifold inlet, and the lateraltranslation region located downstream from the transverse expansionregion and upstream from the crossflow manifold outlet, the transverseexpansion region exhibiting a transverse expansion of the respectivecrossflow manifold body relative to a longitudinal axis of therespective crossflow manifold inlet and/or relative to a lateral axis ofthe crossflow manifold outlet, and the lateral translation regionexhibiting a lateral translation in an axial orientation of therespective crossflow manifold body relative to the longitudinal axis ofthe respective crossflow manifold inlet and/or relative to a lateralaxis of the crossflow manifold outlet.
 2. The build unit of claim 1,wherein the crossflow manifold comprises a plurality of crossflowmanifold pathway walls, the plurality of crossflow manifold pathwaywalls respectively defining at least a portion of respective ones of theplurality of crossflow manifold pathways.
 3. The build unit of claim 1,wherein respective ones of the plurality of crossflow manifold bodiescomprise a longitudinal extension region disposed between at least aportion of the transverse expansion region and at least a portion of thelateral translation region, the longitudinal extension region exhibitinga longitudinal extension in the respective crossflow manifold bodyrelative to the longitudinal axis of the respective crossflow manifoldinlet.
 4. The build unit of claim 1, wherein respective ones of theplurality of crossflow manifold bodies comprise a lateral profilingregion coinciding with a location of at least a portion of thetransverse expansion region and/or at least a portion of the lateraltranslation region, the lateral profiling region exhibiting a lateralchange in cross-sectional profile of the respective crossflow manifoldbody relative to a cross-sectional profile of the respective crossflowmanifold inlet.
 5. The build unit of claim 1, wherein the crossflowmanifold comprises a plurality of inlet flow conditioners, respectiveones of the plurality of inlet flow conditioners disposed in arespective crossflow manifold inlet.
 6. The build unit of claim 5,wherein respective ones of the plurality of inlet flow conditionerscomprise a lattice defining a plurality of inlet flow conditioningchannels, respective ones of the plurality of inlet flow conditioningchannels comprising a polygonal cross-sectional profile, an ellipticalcross-sectional profile, and/or a curvilinear cross-sectional profile.7. The build unit of claim 5, wherein respective ones of the pluralityof inlet flow conditioners are removably and/or fixedly inserted withinthe respective crossflow manifold inlet, or wherein respective ones ofthe plurality of inlet flow conditioners are integrally formed as partof the respective crossflow manifold body defining the respectivecrossflow manifold inlet.
 8. The build unit of claim 1, wherein thecrossflow manifold comprises an outlet flow conditioner disposed in thecrossflow manifold outlet.
 9. The build unit of claim 8, wherein theoutlet flow conditioner comprises a lattice defining a plurality ofoutlet flow conditioning channels, respective ones of the plurality ofoutlet flow conditioning channels comprising a polygonal cross-sectionalprofile, an elliptical cross-sectional profile, and/or a curvilinearcross-sectional profile.
 10. The build unit of claim 9, wherein at leastsome of the plurality of outlet flow conditioning channels have anoblique orientation that converges towards a lateral axis of thecrossflow manifold outlet in a direction of a flow of process gasthrough the plurality of outlet flow conditioning channels.
 11. Thebuild unit of claim 10, wherein at least some of the plurality of outletflow conditioning channels are oriented relative to a normal lineperpendicular to a tangent of a curvilinear plane, the curvilinear planecorresponding to a portion of a sphere or an ovoid.
 12. The build unitof claim 8, wherein the outlet flow conditioner is removably and/orfixedly inserted within the crossflow manifold outlet, or wherein theoutlet flow conditioner is integrally formed as part of the plurality ofcrossflow manifold bodies defining the crossflow manifold outlet. 13.The build unit of claim 8, wherein the plurality of crossflow manifoldbodies comprises one or more crossflow manifold sidewalls with an outletflow conditioner access port configured to receive the outlet flowconditioner.
 14. The build unit of claim 8, wherein the plurality ofcrossflow manifold bodies comprises one or more outlet flow conditionerslots configured to receive an outflow conditioner, the one or moreoutlet flow conditioner slots extending transversely across theplurality of crossflow manifold bodies adjacent to and/or upstream fromthe crossflow manifold outlet.
 15. The build unit of claim 1,comprising: a supply manifold header configured to distribute processgas to the one or more supply manifolds; and a plurality of process gassupply lines, respective ones of the process gas supply lines fluidlycommunicating between the supply manifold header and the respectivecrossflow manifold inlet.
 16. The build unit of claim 15, comprising:one or more supply header conjunction elements, respective ones of theone or more supply header conjunction elements fluidly communicatingbetween a respective first and second ones of the plurality of processgas supply lines, the one or more supply header conjunction elementsconfigured to allow a flow of process gas to distribute proportionallybetween the plurality of process gas supply lines.
 17. The build unit ofclaim 1, wherein the inertization system comprises a return manifoldconfigured to receive and/or evacuate process gas from the irradiationplenum while irradiating the region of the powder bed with the buildunit situated above the region of the powder bed, the process gasflowing through the irradiation plenum and into the return manifoldwhile irradiating the region of the powder bed.
 18. The build unit ofclaim 1, wherein the one or more supply manifolds comprises a downflowmanifold configured to provide a downward flow of the process gasthrough at least a portion of the irradiation plenum defined by theirradiation chamber.
 19. The build unit of claim 1, wherein theirradiation chamber comprises a crossflow chamber defining a crossflowplenum occupying at least a portion of the irradiation plenum, whereinthe crossflow manifold is configured to provide a lateral flow of theprocess gas through the crossflow plenum, and wherein the crossflowchamber comprises one or more crossflow walls oriented parallel oroblique to a lateral axis of the crossflow chamber.
 20. A method ofadditively manufacturing a three-dimensional object, the methodcomprising: irradiating a region of a powder bed with a build unitsituated above the region of the powder bed, the build unit comprisingan energy beam system and an inertization system, the energy beam systemcomprising one or more irradiation devices respectively configured todirect one or more energy beams onto a region of a powder bed, and theinertization system comprising an irradiation chamber defining anirradiation plenum and one or more supply manifolds configured to supplyprocess gas to the irradiation plenum; and flowing a process gas throughthe one or more supply manifolds and into the irradiation plenum whileirradiating the powder bed, wherein the one or more supply manifoldscomprises a crossflow manifold configured to provide a lateral flow ofthe process gas through at least a portion of the irradiation plenumdefined by the irradiation chamber; wherein the crossflow manifoldcomprises a plurality of crossflow manifold bodies arranged along awidth of the crossflow manifold, the plurality of crossflow manifoldbodies respectively coupled to one another or defining a respectiveintegrally formed portion of the crossflow manifold, respective ones ofthe plurality of crossflow manifold bodies comprising a crossflowmanifold inlet fluidly communicating with a process gas supply line anda plurality of crossflow manifold pathways defined by the respectivecrossflow manifold body, and the crossflow manifold comprising acrossflow manifold outlet defined at least in part by respective ones ofthe plurality of crossflow manifold bodies, the crossflow manifoldoutlet having an elongate cross-sectional profile, and the crossflowmanifold outlet fluidly communicating with the irradiation plenumdefined by the irradiation chamber and the plurality of crossflowmanifold pathways of the respective ones of the plurality of crossflowmanifold bodies; wherein flowing the process gas through the one or moresupply manifolds and into the irradiation plenum comprises transverselyexpanding the process gas at a transverse expansion region of respectiveones of the plurality of crossflow manifold bodies followed by laterallytranslating the process gas at a lateral translation region ofrespective ones of the plurality of crossflow manifold bodies, thetransverse expansion region located downstream from the respectivecrossflow manifold inlet, and the lateral translation region locateddownstream from the transverse expansion region and upstream from thecrossflow manifold outlet, the transverse expansion region exhibiting atransverse expansion relative to a longitudinal axis of the respectivecrossflow manifold inlet and/or relative to a lateral axis of thecrossflow manifold outlet, and the lateral translation region exhibitinga lateral translation in an axial orientation of the respectivecrossflow manifold body relative to the longitudinal axis of therespective crossflow manifold inlet and/or relative to a lateral axis ofthe crossflow manifold outlet.